Merge branch 'master' into oc_error

26 files changed, 606 insertions, 167 deletions

diff --git a/lib/app.php b/lib/app.php
index 124b76cdc3d..667633e2647 100755
--- a/lib/app.php
+++ b/lib/app.php
@@ -35,6 +35,7 @@ class OC_App{
 	static private $personalForms = array();
 	static private $appInfo = array();
 	static private $appTypes = array();
+	static private $loadedApps = array();
 
 	/**
 	 * @brief loads all apps
@@ -48,24 +49,26 @@ class OC_App{
 	 * if $types is set, only apps of those types will be loaded
 	 */
 	public static function loadApps($types=null){
-		// Did we already load everything?
-		if( self::$init ){
-			return true;
-		}
-
 		// Load the enabled apps here
 		$apps = self::getEnabledApps();
 		// prevent app.php from printing output
 		ob_start();
 		foreach( $apps as $app ){
-			if((is_null($types) or self::isType($app,$types))){
+			if((is_null($types) or self::isType($app,$types)) && !in_array($app, self::$loadedApps)){
 				self::loadApp($app);
+				self::$loadedApps[] = $app;
 			}
 		}
 		ob_end_clean();
 
-		self::$init = true;
-
+		if (!defined('DEBUG') || !DEBUG){
+			if (is_null($types)) {
+				OC_Util::$core_scripts = OC_Util::$scripts;
+				OC_Util::$scripts = array();
+				OC_Util::$core_styles = OC_Util::$styles;
+				OC_Util::$styles = array();
+			}
+		}
 		// return
 		return true;
 	}
@@ -121,7 +124,7 @@ class OC_App{
 	 */
 	public static function setAppTypes($app){
 		$appData=self::getAppInfo($app);
-		
+
 		if(isset($appData['types'])){
 			$appTypes=implode(',',$appData['types']);
 		}else{
@@ -183,7 +186,7 @@ class OC_App{
 		if($app!==false){
 			// check if the app is compatible with this version of ownCloud
 			$info=OC_App::getAppInfo($app);
-			$version=OC_Util::getVersion();	
+			$version=OC_Util::getVersion();
 	                if(!isset($info['require']) or ($version[0]>$info['require'])){
 				OC_Log::write('core','App "'.$info['name'].'" can\'t be installed because it is not compatible with this version of ownCloud',OC_Log::ERROR);
 				return false;
@@ -487,13 +490,13 @@ class OC_App{
 				}
 			}
 		}
-		
+
 		// check if the current enabled apps are compatible with the current ownCloud version. disable them if not.
 		// this is important if you upgrade ownCloud and have non ported 3rd party apps installed
 		$apps =OC_App::getEnabledApps();
 		$version=OC_Util::getVersion();
 		foreach($apps as $app) {
-		
+
 			// check if the app is compatible with this version of ownCloud
 			$info=OC_App::getAppInfo($app);
 			if(!isset($info['require']) or ($version[0]>$info['require'])){
@@ -501,12 +504,12 @@ class OC_App{
 				OC_App::disable( $app );
 			}
 
-	
-			
+
+
 		}
-		
-		
-		
+
+
+
 	}
 
 	/**
diff --git a/lib/base.php b/lib/base.php
index e6fcb9ec4de..a439651f4a6 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -31,17 +31,13 @@ class OC{
 	 */
 	public static $CLASSPATH = array();
 	/**
-	 * $_SERVER['DOCUMENTROOT'] but without symlinks
-	 */
-	public static $DOCUMENTROOT = '';
-	/**
 	 * The installation path for owncloud on the server (e.g. /srv/http/owncloud)
 	 */
 	public static $SERVERROOT = '';
 	/**
 	 * the current request path relative to the owncloud root (e.g. files/index.php)
 	 */
-	public static $SUBURI = '';
+	private static $SUBURI = '';
 	/**
 	 * the owncloud root path for http requests (e.g. owncloud/)
 	 */
@@ -51,10 +47,6 @@ class OC{
 	 */
 	public static $CONFIG_DATADIRECTORY = '';
 	/**
-	 * the folder that stores the data for the root filesystem (e.g. /srv/http/owncloud/data)
-	 */
-	public static $CONFIG_DATADIRECTORY_ROOT = '';
-	/**
 	 * The installation path of the 3rdparty folder on the server (e.g. /srv/http/owncloud/3rdparty)
 	 */
 	public static $THIRDPARTYROOT = '';
@@ -130,7 +122,7 @@ class OC{
 
 	public static function initPaths(){
 		// calculate the documentroot
-		OC::$DOCUMENTROOT=realpath($_SERVER['DOCUMENT_ROOT']);
+		$DOCUMENTROOT=realpath($_SERVER['DOCUMENT_ROOT']);
 		OC::$SERVERROOT=str_replace("\\",'/',substr(__FILE__,0,-13));
 		OC::$SUBURI=substr(realpath($_SERVER["SCRIPT_FILENAME"]),strlen(OC::$SERVERROOT));
 		$scriptName=$_SERVER["SCRIPT_NAME"];
@@ -146,7 +138,7 @@ class OC{
 		}
                 OC::$WEBROOT=substr($scriptName,0,strlen($scriptName)-strlen(OC::$SUBURI));
 		// try a new way to detect the WEBROOT which is simpler and also works with the app directory outside the owncloud folder. let´s see if this works for everybody
-//		OC::$WEBROOT=substr(OC::$SERVERROOT,strlen(OC::$DOCUMENTROOT));
+//		OC::$WEBROOT=substr(OC::$SERVERROOT,strlen($DOCUMENTROOT));
 
 
 		if(OC::$WEBROOT!='' and OC::$WEBROOT[0]!=='/'){
@@ -291,18 +283,9 @@ class OC{
 	public static function loadfile(){
 		if(file_exists(OC::$APPSROOT . '/apps/' . OC::$REQUESTEDAPP . '/' . OC::$REQUESTEDFILE)){
 			if(substr(OC::$REQUESTEDFILE, -3) == 'css'){
-				$appswebroot = (string) OC::$APPSWEBROOT;
-				$webroot = (string) OC::$WEBROOT;
-				$filepath = OC::$APPSROOT . '/apps/' . OC::$REQUESTEDAPP . '/' . OC::$REQUESTEDFILE;
-				header('Content-Type: text/css');
-				OC_Response::enableCaching();
-				OC_Response::setLastModifiedHeader(filemtime($filepath));
-				$cssfile = file_get_contents($filepath);
-				$cssfile = str_replace('%appswebroot%', $appswebroot, $cssfile);
-				$cssfile = str_replace('%webroot%', $webroot, $cssfile);
-				OC_Response::setETagHeader(md5($cssfile));
-				header('Content-Length: '.strlen($cssfile));
-				echo $cssfile;
+				$file = 'apps/' . OC::$REQUESTEDAPP . '/' . OC::$REQUESTEDFILE;
+				$minimizer = new OC_Minimizer_CSS();
+				$minimizer->output(array(array(OC::$APPSROOT, OC::$APPSWEBROOT, $file)));
 				exit;
 			}elseif(substr(OC::$REQUESTEDFILE, -3) == 'php'){
 				require_once(OC::$APPSROOT . '/apps/' . OC::$REQUESTEDAPP . '/' . OC::$REQUESTEDFILE);
@@ -381,16 +364,18 @@ class OC{
 
 		// CSRF protection
 		if(isset($_SERVER['HTTP_REFERER'])) $referer=$_SERVER['HTTP_REFERER']; else $referer='';
-		$protocol=OC_Helper::serverProtocol().'://'; 
+		$refererhost=parse_url($referer);
+		if(isset($refererhost['host'])) $refererhost=$refererhost['host']; else $refererhost='';
+		$server=OC_Helper::serverHost();
+		$serverhost=explode(':',$server);
+		$serverhost=$serverhost['0']; 
 		if(!self::$CLI){
-			$server=$protocol.OC_Helper::serverHost();
-			if(($_SERVER['REQUEST_METHOD']=='POST') and (substr($referer,0,strlen($server))<>$server)) {
-				$url = $protocol.OC_Helper::serverProtocol().OC::$WEBROOT.'/index.php';
+			if(($_SERVER['REQUEST_METHOD']=='POST') and ($refererhost<>$serverhost)) {
+				$url = OC_Helper::serverProtocol().'://'.$server.OC::$WEBROOT.'/index.php';
 				header("Location: $url");
 				exit();
 			}
 		}
-
 		self::initSession();
 		self::initTemplateEngine();
 		self::checkUpgrade();
@@ -440,7 +425,12 @@ class OC{
 
 		//make sure temporary files are cleaned up
 		register_shutdown_function(array('OC_Helper','cleanTmp'));
-		
+
+		if (!OC_AppConfig::getValue('core', 'remote_core.css', false)) {
+			OC_AppConfig::setValue('core', 'remote_core.css', '/core/minimizer.php');
+			OC_AppConfig::setValue('core', 'remote_core.js', '/core/minimizer.php');
+		}
+
 		//parse the given parameters
 		self::$REQUESTEDAPP = (isset($_GET['app'])?str_replace(array('\0', '/', '\\', '..'), '', strip_tags($_GET['app'])):OC_Config::getValue('defaultapp', 'files'));
 		if(substr_count(self::$REQUESTEDAPP, '?') != 0){
diff --git a/lib/cache.php b/lib/cache.php
new file mode 100644
index 00000000000..70f11f35518
--- /dev/null
+++ b/lib/cache.php
@@ -0,0 +1,54 @@
+<?php
+/**
+ * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+class OC_Cache {
+	static protected $cache;
+
+	static protected function init() {
+		self::$cache = new OC_Cache_File();
+	}
+
+	static public function get($key) {
+		if (!self::$cache) {
+			self::init();
+		}
+		return self::$cache->get($key);
+	}
+
+	static public function set($key, $value, $ttl=0) {
+		if (empty($key)) {
+			return false;
+		}
+		if (!self::$cache) {
+			self::init();
+		}
+		return self::$cache->set($key, $value, $ttl);
+	}
+
+	static public function hasKey($key) {
+		if (!self::$cache) {
+			self::init();
+		}
+		return self::$cache->hasKey($key);
+	}
+
+	static public function remove($key) {
+		if (!self::$cache) {
+			self::init();
+		}
+		return self::$cache->remove($key);
+	}
+
+	static public function clear() {
+		if (!self::$cache) {
+			self::init();
+		}
+		return self::$cache->clear();
+	}
+
+}
diff --git a/lib/cache/apc.php b/lib/cache/apc.php
new file mode 100644
index 00000000000..f814afbe494
--- /dev/null
+++ b/lib/cache/apc.php
@@ -0,0 +1,46 @@
+<?php
+/**
+ * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+class OC_Cache_APC {
+	/**
+	 * entries in APC gets namespaced to prevent collisions between owncloud instances and users
+	 */
+	protected function getNameSpace() {
+		return OC_Util::getInstanceId().'/'.OC_User::getUser().'/';
+	}
+
+	public function get($key) {
+		$result = apc_fetch($this->getNamespace().$key, $success);
+		if (!$success) {
+			return null;
+		}
+		return $result;
+	}
+
+	public function set($key, $value, $ttl=0) {
+		return apc_store($this->getNamespace().$key, $value, $ttl);
+	}
+
+	public function hasKey($key) {
+		return apc_exists($this->getNamespace().$key);
+	}
+
+	public function remove($key) {
+		return apc_delete($this->getNamespace().$key);
+	}
+
+	public function clear(){
+		$ns = $this->getNamespace();
+		$cache = apc_cache_info('user');
+		foreach($cache['cache_list'] as $entry) {
+			if (strpos($entry['info'], $ns) === 0) {
+				apc_delete($entry['info']);
+			}
+		}
+	}
+}
diff --git a/lib/cache/file.php b/lib/cache/file.php
new file mode 100644
index 00000000000..0b7d3e30508
--- /dev/null
+++ b/lib/cache/file.php
@@ -0,0 +1,76 @@
+<?php
+/**
+ * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+
+class OC_Cache_File{
+	protected function getStorage() {
+		if(OC_User::isLoggedIn()){
+			$subdir = 'cache';
+			$view = new OC_FilesystemView('/'.OC_User::getUser());
+			if(!$view->file_exists($subdir)) {
+				$view->mkdir($subdir);
+			}
+			return new OC_FilesystemView('/'.OC_User::getUser().'/'.$subdir);
+		}else{
+			OC_Log::write('core','Can\'t get cache storage, user not logged in', OC_Log::ERROR);
+			return false;
+		}
+	}
+
+	public function get($key) {
+		if ($this->hasKey($key)) {
+			$storage = $this->getStorage();
+			return $storage->file_get_contents($key);
+		}
+		return null;
+	}
+
+	public function set($key, $value, $ttl=0) {
+		$storage = $this->getStorage();
+		if ($storage and $storage->file_put_contents($key, $value)) {
+			if ($ttl === 0) {
+				$ttl = 86400; // 60*60*24
+			}
+			return $storage->touch($key, time() + $ttl);
+		}
+		return false;
+	}
+
+	public function hasKey($key) {
+		$storage = $this->getStorage();
+		if ($storage && $storage->is_file($key)) {
+			$mtime = $storage->filemtime($key);
+			if ($mtime < time()) {
+				$storage->unlink($key);
+				return false;
+			}
+			return true;
+		}
+		return false;
+	}
+
+	public function remove($key) {
+		$storage = $this->getStorage();
+		if(!$storage){
+			return false;
+		}
+		return $storage->unlink($key);
+	}
+
+	public function clear(){
+		$storage = $this->getStorage();
+		if($storage and $storage->is_dir('/')){
+			$dh=$storage->opendir('/');
+			while($file=readdir($dh)){
+				if($file!='.' and $file!='..'){
+					$storage->unlink('/'.$file);
+				}
+			}
+		}
+	}
+}
diff --git a/lib/cache/xcache.php b/lib/cache/xcache.php
new file mode 100644
index 00000000000..b57338929e0
--- /dev/null
+++ b/lib/cache/xcache.php
@@ -0,0 +1,40 @@
+<?php
+/**
+ * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+class OC_Cache_XCache {
+	/**
+	 * entries in XCache gets namespaced to prevent collisions between owncloud instances and users
+	 */
+	protected function getNameSpace() {
+		return OC_Util::getInstanceId().'/'.OC_User::getUser().'/';
+	}
+
+	public function get($key) {
+		return xcache_get($this->getNamespace().$key);
+	}
+
+	public function set($key, $value, $ttl=0) {
+		if($ttl>0){
+			return xcache_set($this->getNamespace().$key,$value,$ttl);
+		}else{
+			return xcache_set($this->getNamespace().$key,$value);
+		}
+	}
+
+	public function hasKey($key) {
+		return xcache_isset($this->getNamespace().$key);
+	}
+
+	public function remove($key) {
+		return xcache_unset($this->getNamespace().$key);
+	}
+
+	public function clear(){
+		return xcache_unset_by_prefix($this->getNamespace());
+	}
+}
diff --git a/lib/connector/sabre/directory.php b/lib/connector/sabre/directory.php
index 935d3b0abe4..e74d832cb00 100644
--- a/lib/connector/sabre/directory.php
+++ b/lib/connector/sabre/directory.php
@@ -118,8 +118,10 @@ class OC_Connector_Sabre_Directory extends OC_Connector_Sabre_Node implements Sa
 	 */
 	public function delete() {
 
-		foreach($this->getChildren() as $child) $child->delete();
-		OC_Filesystem::rmdir($this->path);
+		if ($this->path != "/Shared") {
+			foreach($this->getChildren() as $child) $child->delete();
+			OC_Filesystem::rmdir($this->path);
+		}
 
 	}
 
diff --git a/lib/filecache.php b/lib/filecache.php
index a29e29928a8..3fb8e4113cb 100644
--- a/lib/filecache.php
+++ b/lib/filecache.php
@@ -169,6 +169,15 @@ class OC_FileCache{
 		$newParent=self::getParentId($newPath);
 		$query=OC_DB::prepare('UPDATE *PREFIX*fscache SET parent=? ,name=?, path=?, path_hash=? WHERE path_hash=?');
 		$query->execute(array($newParent,basename($newPath),$newPath,md5($newPath),md5($oldPath)));
+
+		$query=OC_DB::prepare('SELECT path FROM *PREFIX*fscache WHERE path LIKE ?');
+		$oldLength=strlen($oldPath);
+		$updateQuery=OC_DB::prepare('UPDATE *PREFIX*fscache SET path=?, path_hash=? WHERE path_hash=?');
+		while($row= $query->execute(array($oldPath.'/%'))->fetchRow()){
+			$old=$row['path'];
+			$new=$newPath.substr($old,$oldLength);
+			$updateQuery->execute(array($new,md5($new),md5($old)));
+		}
 	}
 
 	/**
diff --git a/lib/files.php b/lib/files.php
index 79d214665de..705b7a6ca66 100644
--- a/lib/files.php
+++ b/lib/files.php
@@ -170,7 +170,7 @@ class OC_Files {
 	* @param file $target
 	*/
 	public static function move($sourceDir,$source,$targetDir,$target){
-		if(OC_User::isLoggedIn()){
+		if(OC_User::isLoggedIn() && ($sourceDir != '' || $source != 'Shared')){
 			$targetFile=self::normalizePath($targetDir.'/'.$target);
 			$sourceFile=self::normalizePath($sourceDir.'/'.$source);
 			return OC_Filesystem::rename($sourceFile,$targetFile);
@@ -224,7 +224,7 @@ class OC_Files {
 	* @param file $name
 	*/
 	public static function delete($dir,$file){
-		if(OC_User::isLoggedIn()){
+		if(OC_User::isLoggedIn() && ($dir!= '' || $file != 'Shared')) {
 			$file=$dir.'/'.$file;
 			return OC_Filesystem::unlink($file);
 		}
@@ -373,10 +373,12 @@ class OC_Files {
 			}
 		}
 
-		//supress errors in case we don't have permissions for it
-		if(@file_put_contents(OC::$SERVERROOT.'/.htaccess', $htaccess)) {
-			return OC_Helper::computerFileSize($size);
-		}
+		//check for write permissions
+		if(is_writable(OC::$SERVERROOT.'/.htaccess')) {
+			file_put_contents(OC::$SERVERROOT.'/.htaccess', $htaccess);
+			return OC_Helper::computerFileSize($size);	
+		} else { OC_Log::write('files','Can\'t write upload limit to '.OC::$SERVERROOT.'/.htaccess. Please check the file permissions',OC_Log::WARN); }
+		
 		return false;
 	}
 
diff --git a/lib/filesystem.php b/lib/filesystem.php
index 6b3c254c5e9..84d45f5f24b 100644
--- a/lib/filesystem.php
+++ b/lib/filesystem.php
@@ -290,8 +290,10 @@ class OC_Filesystem{
 	}
 
 	/**
-	 * get the fake root
+	 * @brief get the relative path of the root data directory for the current user
 	 * @return string
+	 *
+	 * Returns path like /admin/files
 	 */
 	static public function getRoot(){
 		return self::$defaultInstance->getRoot();
diff --git a/lib/group.php b/lib/group.php
index 7967e1a581b..ceee5fa4edb 100644
--- a/lib/group.php
+++ b/lib/group.php
@@ -84,7 +84,7 @@ class OC_Group {
 		OC_Hook::emit( "OC_Group", "pre_createGroup", array( "run" => &$run, "gid" => $gid ));
 
 		if($run){
-			//create the user in the first backend that supports creating users
+			//create the group in the first backend that supports creating groups
 			foreach(self::$_usedBackends as $backend){
 				if(!$backend->implementsActions(OC_GROUP_BACKEND_CREATE_GROUP))
 					continue;
@@ -141,9 +141,6 @@ class OC_Group {
 	 */
 	public static function inGroup( $uid, $gid ){
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_IN_GROUP))
-				continue;
-
 			if($backend->inGroup($uid,$gid)){
 				return true;
 			}
@@ -228,9 +225,6 @@ class OC_Group {
 	public static function getUserGroups( $uid ){
 		$groups=array();
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_GET_USER_GROUPS))
-				continue;
-
 			$groups=array_merge($backend->getUserGroups($uid),$groups);
 		}
 		asort($groups);
@@ -246,9 +240,6 @@ class OC_Group {
 	public static function getGroups(){
 		$groups=array();
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_GET_GROUPS))
-				continue;
-
 			$groups=array_merge($backend->getGroups(),$groups);
 		}
 		asort($groups);
@@ -276,9 +267,6 @@ class OC_Group {
 	public static function usersInGroup($gid){
 		$users=array();
 		foreach(self::$_usedBackends as $backend){
-			if(!$backend->implementsActions(OC_GROUP_BACKEND_GET_USERS))
-				continue;
-
 			$users=array_merge($backend->usersInGroup($gid),$users);
 		}
 		return $users;
diff --git a/lib/group/backend.php b/lib/group/backend.php
index 3b652599462..24778afd1e5 100644
--- a/lib/group/backend.php
+++ b/lib/group/backend.php
@@ -31,12 +31,8 @@ define('OC_GROUP_BACKEND_NOT_IMPLEMENTED',   -501);
  */
 define('OC_GROUP_BACKEND_CREATE_GROUP',      0x00000001);
 define('OC_GROUP_BACKEND_DELETE_GROUP',      0x00000010);
-define('OC_GROUP_BACKEND_IN_GROUP',          0x00000100);
-define('OC_GROUP_BACKEND_ADD_TO_GROUP',      0x00001000);
-define('OC_GROUP_BACKEND_REMOVE_FROM_GOUP',  0x00010000);
-define('OC_GROUP_BACKEND_GET_USER_GROUPS',   0x00100000);
-define('OC_GROUP_BACKEND_GET_USERS',         0x01000000);
-define('OC_GROUP_BACKEND_GET_GROUPS',        0x10000000);
+define('OC_GROUP_BACKEND_ADD_TO_GROUP',      0x00000100);
+define('OC_GROUP_BACKEND_REMOVE_FROM_GOUP',  0x00001000);
 
 /**
  * Abstract base class for user management
@@ -45,14 +41,10 @@ abstract class OC_Group_Backend {
 	protected $possibleActions = array(
 		OC_GROUP_BACKEND_CREATE_GROUP => 'createGroup',
 		OC_GROUP_BACKEND_DELETE_GROUP => 'deleteGroup',
-		OC_GROUP_BACKEND_IN_GROUP => 'inGroup',
 		OC_GROUP_BACKEND_ADD_TO_GROUP => 'addToGroup',
 		OC_GROUP_BACKEND_REMOVE_FROM_GOUP => 'removeFromGroup',
-		OC_GROUP_BACKEND_GET_USER_GROUPS => 'getUserGroups',
-		OC_GROUP_BACKEND_GET_USERS => 'usersInGroup',
-		OC_GROUP_BACKEND_GET_GROUPS => 'getGroups'
 	);
-	
+
 	/**
 	* @brief Get all supported actions
 	* @returns bitwise-or'ed actions
@@ -70,7 +62,7 @@ abstract class OC_Group_Backend {
 
 		return $actions;
 	}
-	
+
 	/**
 	* @brief Check if backend implements actions
 	* @param $actions bitwise-or'ed actions
@@ -84,14 +76,54 @@ abstract class OC_Group_Backend {
 	}
 
 	/**
+	 * @brief is user in group?
+	 * @param $uid uid of the user
+	 * @param $gid gid of the group
+	 * @returns true/false
+	 *
+	 * Checks whether the user is member of a group or not.
+	 */
+	public function inGroup($uid, $gid){
+		return in_array($gid, $this->getUserGroups($uid));
+	}
+
+	/**
+	 * @brief Get all groups a user belongs to
+	 * @param $uid Name of the user
+	 * @returns array with group names
+	 *
+	 * This function fetches all groups a user belongs to. It does not check
+	 * if the user exists at all.
+	 */
+	public function getUserGroups($uid){
+		return array();
+	}
+
+	/**
+	 * @brief get a list of all groups
+	 * @returns array with group names
+	 *
+	 * Returns a list with all groups
+	 */
+	public function getGroups(){
+		return array();
+	}
+
+	/**
 	 * check if a group exists
 	 * @param string $gid
 	 * @return bool
 	 */
 	public function groupExists($gid){
-		if(!$this->implementsActions(OC_GROUP_BACKEND_GET_GROUPS)){
-			return false;
-		}
 		return in_array($gid, $this->getGroups());
 	}
+
+	/**
+	 * @brief get a list of all users in a group
+	 * @returns array with user ids
+	 */
+	public function usersInGroup($gid){
+		return array();
+	}
+
 }
diff --git a/lib/group/database.php b/lib/group/database.php
index af55de1f427..fb173665eb8 100644
--- a/lib/group/database.php
+++ b/lib/group/database.php
@@ -41,7 +41,7 @@
  * Class for group management in a SQL Database (e.g. MySQL, SQLite)
  */
 class OC_Group_Database extends OC_Group_Backend {
-	static private $userGroupCache=array();
+	private $userGroupCache=array();
 
 	/**
 	 * @brief Try to create a new group
@@ -51,7 +51,7 @@ class OC_Group_Database extends OC_Group_Backend {
 	 * Trys to create a new group. If the group name already exists, false will
 	 * be returned.
 	 */
-	public static function createGroup( $gid ){
+	public function createGroup( $gid ){
 		// Check for existence
 		$query = OC_DB::prepare( "SELECT gid FROM `*PREFIX*groups` WHERE gid = ?" );
 		$result = $query->execute( array( $gid ));
@@ -76,7 +76,7 @@ class OC_Group_Database extends OC_Group_Backend {
 	 *
 	 * Deletes a group and removes it from the group_user-table
 	 */
-	public static function deleteGroup( $gid ){
+	public function deleteGroup( $gid ){
 		// Delete the group
 		$query = OC_DB::prepare( "DELETE FROM `*PREFIX*groups` WHERE gid = ?" );
 		$result = $query->execute( array( $gid ));
@@ -96,7 +96,7 @@ class OC_Group_Database extends OC_Group_Backend {
 	 *
 	 * Checks whether the user is member of a group or not.
 	 */
-	public static function inGroup( $uid, $gid ){
+	public function inGroup( $uid, $gid ){
 		// check
 		$query = OC_DB::prepare( "SELECT uid FROM `*PREFIX*group_user` WHERE gid = ? AND uid = ?" );
 		$result = $query->execute( array( $gid, $uid ));
@@ -112,9 +112,9 @@ class OC_Group_Database extends OC_Group_Backend {
 	 *
 	 * Adds a user to a group.
 	 */
-	public static function addToGroup( $uid, $gid ){
+	public function addToGroup( $uid, $gid ){
 		// No duplicate entries!
-		if( !self::inGroup( $uid, $gid )){
+		if( !$this->inGroup( $uid, $gid )){
 			$query = OC_DB::prepare( "INSERT INTO `*PREFIX*group_user` ( `uid`, `gid` ) VALUES( ?, ? )" );
 			$result = $query->execute( array( $uid, $gid ));
 			return true;
@@ -131,7 +131,7 @@ class OC_Group_Database extends OC_Group_Backend {
 	 *
 	 * removes the user from a group.
 	 */
-	public static function removeFromGroup( $uid, $gid ){
+	public function removeFromGroup( $uid, $gid ){
 		$query = OC_DB::prepare( "DELETE FROM *PREFIX*group_user WHERE uid = ? AND gid = ?" );
 		$result = $query->execute( array( $uid, $gid ));
 
@@ -146,7 +146,7 @@ class OC_Group_Database extends OC_Group_Backend {
 	 * This function fetches all groups a user belongs to. It does not check
 	 * if the user exists at all.
 	 */
-	public static function getUserGroups( $uid ){
+	public function getUserGroups( $uid ){
 		// No magic!
 		$query = OC_DB::prepare( "SELECT gid FROM `*PREFIX*group_user` WHERE uid = ?" );
 		$result = $query->execute( array( $uid ));
@@ -165,7 +165,7 @@ class OC_Group_Database extends OC_Group_Backend {
 	 *
 	 * Returns a list with all groups
 	 */
-	public static function getGroups(){
+	public function getGroups(){
 		$query = OC_DB::prepare( "SELECT gid FROM `*PREFIX*groups`" );
 		$result = $query->execute();
 
@@ -176,12 +176,12 @@ class OC_Group_Database extends OC_Group_Backend {
 
 		return $groups;
 	}
-	
+
 	/**
 	 * @brief get a list of all users in a group
 	 * @returns array with user ids
 	 */
-	public static function usersInGroup($gid){
+	public function usersInGroup($gid){
 		$query=OC_DB::prepare('SELECT uid FROM *PREFIX*group_user WHERE gid=?');
 		$users=array();
 		$result=$query->execute(array($gid));
diff --git a/lib/group/example.php b/lib/group/example.php
index b2de119553c..c18562db7a4 100644
--- a/lib/group/example.php
+++ b/lib/group/example.php
@@ -94,6 +94,13 @@ abstract class OC_Group_Example {
 	public static function getGroups(){}
 
 	/**
+	 * check if a group exists
+	 * @param string $gid
+	 * @return bool
+	 */
+	public function groupExists($gid){}
+
+	/**
 	 * @brief get a list of all users in a group
 	 * @returns array with user ids
 	 */
diff --git a/lib/helper.php b/lib/helper.php
index f8f84b91ae3..decc1d61336 100644
--- a/lib/helper.php
+++ b/lib/helper.php
@@ -120,7 +120,7 @@ class OC_Helper {
 	 */
 	public static function linkToAbsolute( $app, $file ) {
 		$urlLinkTo = self::linkTo( $app, $file );
-		$urlLinkTo = OC_Helper::serverProtocol(). '://'  . self::serverHost() . $urlLinkTo;
+		$urlLinkTo = self::serverProtocol(). '://'  . self::serverHost() . $urlLinkTo;
 		return $urlLinkTo;
 	}
 
@@ -131,8 +131,8 @@ class OC_Helper {
 	 *
 	 * Returns a absolute url to the given service.
 	 */
-	public static function linkToRemote( $service ) {
-		return self::linkToAbsolute( '', 'remote.php') . '/' . $service . '/';
+	public static function linkToRemote( $service, $add_slash = true ) {
+		return self::linkToAbsolute( '', 'remote.php') . '/' . $service . ($add_slash?'/':'');
 	}
 
 	/**
diff --git a/lib/image.php b/lib/image.php
index 4c53dc32f58..a6bb92cea27 100644
--- a/lib/image.php
+++ b/lib/image.php
@@ -187,15 +187,22 @@ class OC_Image {
 	}
 
 	/**
-	* @returns Returns a base64 encoded string suitable for embedding in a VCard.
+	* @returns Returns the raw image data.
 	*/
-	function __toString() {
+	function data() {
 		ob_start();
 		$res = imagepng($this->resource);
 		if (!$res) {
-			OC_Log::write('core','OC_Image->__toString. Error writing image',OC_Log::ERROR);
+			OC_Log::write('core','OC_Image->data. Error getting image data.',OC_Log::ERROR);
 		}
-		return base64_encode(ob_get_clean());
+		return ob_get_clean();
+	}
+
+	/**
+	* @returns Returns a base64 encoded string suitable for embedding in a VCard.
+	*/
+	function __toString() {
+		return base64_encode($this->data());
 	}
 
 	/**
diff --git a/lib/log/owncloud.php b/lib/log/owncloud.php
index 5913d8b5b83..92914af8fca 100644
--- a/lib/log/owncloud.php
+++ b/lib/log/owncloud.php
@@ -63,7 +63,7 @@ class OC_Log_Owncloud {
 		self::init();
 		$minLevel=OC_Config::getValue( "loglevel", OC_Log::WARN );
 		$entries = array();
-		$handle = fopen(self::$logFile, 'r');
+		$handle = @fopen(self::$logFile, 'r');
 		if ($handle) {
 			// Just a guess to set the file pointer to the right spot
 			$maxLineLength = 150;
diff --git a/lib/minimizer.php b/lib/minimizer.php
new file mode 100644
index 00000000000..9f9ef086c4a
--- /dev/null
+++ b/lib/minimizer.php
@@ -0,0 +1,40 @@
+<?php
+
+abstract class OC_Minimizer
+{
+	protected $files = array();
+
+	protected function appendIfExist($root, $webroot, $file) {
+                if (is_file($root.'/'.$file)) {
+			$this->files[] = array($root, $webroot, $file);
+                        return true;
+                }
+                return false;
+	}
+
+	public function getLastModified($files) {
+		$last_modified = 0;
+		foreach($files as $file_info) {
+			$file = $file_info[0] . '/' . $file_info[2];
+			$filemtime = filemtime($file);
+			if ($filemtime > $last_modified) {
+				$last_modified = $filemtime;
+			}
+		}
+		return $last_modified;
+	}
+
+	abstract public function minimizeFiles($files);
+
+	public function output($files) {
+		header('Content-Type: '.$this->contentType);
+		OC_Response::enableCaching();
+		$last_modified = $this->getLastModified($files);
+		OC_Response::setLastModifiedHeader($last_modified);
+
+		$out = $this->minimizeFiles($files);
+		OC_Response::setETagHeader(md5($out));
+		header('Content-Length: '.strlen($out));
+		echo $out;
+	}
+}
diff --git a/lib/minimizer/css.php b/lib/minimizer/css.php
new file mode 100644
index 00000000000..4637417579e
--- /dev/null
+++ b/lib/minimizer/css.php
@@ -0,0 +1,73 @@
+<?php
+
+require_once('mediawiki/CSSMin.php');
+
+class OC_Minimizer_CSS extends OC_Minimizer
+{
+	protected $contentType = 'text/css';
+
+	public function findFiles($styles) {
+		// Read the selected theme from the config file
+		$theme=OC_Config::getValue( "theme" );
+
+		// Read the detected formfactor and use the right file name.
+		$fext = OC_Template::getFormFactorExtension();
+		foreach($styles as $style){
+			// is it in 3rdparty?
+			if($this->appendIfExist(OC::$THIRDPARTYROOT, OC::$THIRDPARTYWEBROOT, $style.'.css')) {
+
+			// or in apps?
+			}elseif($this->appendIfExist(OC::$APPSROOT, OC::$APPSWEBROOT, "apps/$style$fext.css" )) {
+			}elseif($this->appendIfExist(OC::$APPSROOT, OC::$APPSWEBROOT, "apps/$style.css" )) {
+
+			// or in the owncloud root?
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "$style$fext.css" )) {
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "$style.css" )) {
+
+			// or in core ?
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "core/$style$fext.css" )) {
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "core/$style.css" )) {
+
+			}else{
+				echo('css file not found: style:'.$style.' formfactor:'.$fext.' webroot:'.OC::$WEBROOT.' serverroot:'.OC::$SERVERROOT);
+				die();
+			}
+		}
+		// Add the theme css files. you can override the default values here
+		if(!empty($theme)) {
+			foreach($styles as $style){
+				     if($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/apps/$style$fext.css" )) {
+				}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/apps/$style.css" )) {
+
+				}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/$style$fext.css" )) {
+				}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/$style.css" )) {
+
+				}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/core/$style$fext.css" )) {
+				}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/core/$style.css" )) {
+				}
+			}
+		}
+		return $this->files;
+	}
+
+	public function minimizeFiles($files) {
+		$css_out = '';
+		$appswebroot = (string) OC::$APPSWEBROOT;
+		$webroot = (string) OC::$WEBROOT;
+		foreach($files as $file_info) {
+			$file = $file_info[0] . '/' . $file_info[2];
+			$css_out .= '/* ' . $file . ' */' . "\n";
+			$css = file_get_contents($file);
+			if (strpos($file, OC::$APPSROOT) == 0) {
+				$css = str_replace('%appswebroot%', $appswebroot, $css);
+				$css = str_replace('%webroot%', $webroot, $css);
+			}
+			$remote = $file_info[1];
+			$remote .= '/';
+			$remote .= dirname($file_info[2]);
+			$css_out .= CSSMin::remap($css, dirname($file), $remote, true);
+		}
+		$css_out = CSSMin::minify($css_out);
+		return $css_out;
+	}
+}
diff --git a/lib/minimizer/js.php b/lib/minimizer/js.php
new file mode 100644
index 00000000000..4ddaa79d81a
--- /dev/null
+++ b/lib/minimizer/js.php
@@ -0,0 +1,62 @@
+<?php
+
+require_once('mediawiki/JavaScriptMinifier.php');
+
+class OC_Minimizer_JS extends OC_Minimizer
+{
+	protected $contentType = 'application/javascript';
+
+	public function findFiles($scripts) {
+		// Read the selected theme from the config file
+		$theme=OC_Config::getValue( "theme" );
+
+		// Read the detected formfactor and use the right file name.
+		$fext = OC_Template::getFormFactorExtension();
+		// Add the core js files or the js files provided by the selected theme
+		foreach($scripts as $script){
+			// Is it in 3rd party?
+			if($this->appendIfExist(OC::$THIRDPARTYROOT, OC::$THIRDPARTYWEBROOT, $script.'.js')) {
+
+			// Is it in apps and overwritten by the theme?
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/apps/$script$fext.js" )) {
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/apps/$script.js" )) {
+
+			// Is it part of an app?
+			}elseif($this->appendIfExist(OC::$APPSROOT, OC::$APPSWEBROOT, "apps/$script$fext.js" )) {
+			}elseif($this->appendIfExist(OC::$APPSROOT, OC::$APPSWEBROOT, "apps/$script.js" )) {
+
+			// Is it in the owncloud root but overwritten by the theme?
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/$script$fext.js" )) {
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/$script.js" )) {
+
+			// Is it in the owncloud root ?
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "$script$fext.js" )) {
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "$script.js" )) {
+
+			// Is in core but overwritten by a theme?
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/core/$script$fext.js" )) {
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "themes/$theme/core/$script.js" )) {
+
+			// Is it in core?
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "core/$script$fext.js" )) {
+			}elseif($this->appendIfExist(OC::$SERVERROOT, OC::$WEBROOT, "core/$script.js" )) {
+
+			}else{
+				echo('js file not found: script:'.$script.' formfactor:'.$fext.' webroot:'.OC::$WEBROOT.' serverroot:'.OC::$SERVERROOT);
+				die();
+			}
+		}
+		return $this->files;
+	}
+
+	public function minimizeFiles($files) {
+		$js_out = '';
+		foreach($files as $file_info) {
+			$file = $file_info[0] . '/' . $file_info[2];
+			$js_out .= '/* ' . $file . ' */' . "\n";
+			$js_out .= file_get_contents($file);
+		}
+		$js_out = JavaScriptMinifier::minify($js_out);
+		return $js_out;
+	}
+}
diff --git a/lib/public/app.php b/lib/public/app.php
index 1f84087f076..9e2108818bf 100644
--- a/lib/public/app.php
+++ b/lib/public/app.php
@@ -36,7 +36,8 @@ namespace OCP;
 class App {
 
         /**
-         * @brief makes owncloud aware of this app
+         * @brief Makes owncloud aware of this app
+         * @brief This call is deprecated and not necessary to use.
          * @param $data array with all information
          * @returns true/false
          *
diff --git a/lib/template.php b/lib/template.php
index a15cfcc457b..14833a1e5b5 100644
--- a/lib/template.php
+++ b/lib/template.php
@@ -166,7 +166,7 @@ class OC_Template{
 	/**
 	 * @brief Returns the formfactor extension for current formfactor
 	 */
-	protected function getFormFactorExtension()
+	static public function getFormFactorExtension()
 	{
 		$formfactor=$_SESSION['formfactor'];
 		if($formfactor=='default') { 
@@ -196,7 +196,7 @@ class OC_Template{
 		$theme=OC_Config::getValue( "theme" );
 
 		// Read the detected formfactor and use the right file name.
-		$fext = $this->getFormFactorExtension();
+		$fext = self::getFormFactorExtension();
 
 		$app = $this->application;
 		// Check if it is a app template or not.
@@ -379,8 +379,9 @@ class OC_Template{
 			$theme=OC_Config::getValue( "theme" );
 
 			// Read the detected formfactor and use the right file name.
-			$fext = $this->getFormFactorExtension();
+			$fext = self::getFormFactorExtension();
 
+			$page->assign('jsfiles', array());
 			// Add the core js files or the js files provided by the selected theme
 			foreach(OC_Util::$scripts as $script){
 				// Is it in 3rd party?
@@ -417,6 +418,7 @@ class OC_Template{
 				}
 			}
 			// Add the css files
+			$page->assign('cssfiles', array());
 			foreach(OC_Util::$styles as $style){
 				// is it in 3rdparty?
                                 if($page->appendIfExist('cssfiles', OC::$THIRDPARTYROOT, OC::$THIRDPARTYWEBROOT, $style.'.css')) {
@@ -434,7 +436,7 @@ class OC_Template{
 				}elseif($page->appendIfExist('cssfiles', OC::$SERVERROOT, OC::$WEBROOT, "core/$style.css" )) {
 
 				}else{
-					echo('css file not found: style:'.$script.' formfactor:'.$fext.' webroot:'.OC::$WEBROOT.' serverroot:'.OC::$SERVERROOT);
+					echo('css file not found: style:'.$style.' formfactor:'.$fext.' webroot:'.OC::$WEBROOT.' serverroot:'.OC::$SERVERROOT);
 					die();
 				}
 			}
diff --git a/lib/user.php b/lib/user.php
index 17c11322b80..f1903093d6d 100644
--- a/lib/user.php
+++ b/lib/user.php
@@ -129,7 +129,7 @@ class OC_User {
 		if(trim($password) == ''){
 			throw new Exception('A valid password must be provided');
 		}
-		
+
 		// Check if user already exists
 		if( self::userExists($uid) ){
 			throw new Exception('The username is already being used');
@@ -168,9 +168,7 @@ class OC_User {
 		if( $run ){
 			//delete the user from all backends
 			foreach(self::$_usedBackends as $backend){
-				if($backend->implementsActions(OC_USER_BACKEND_DELETE_USER)){
-					$backend->deleteUser($uid);
-				}
+				$backend->deleteUser($uid);
 			}
 			// We have to delete the user from all groups
 			foreach( OC_Group::getUserGroups( $uid ) as $i ){
@@ -242,12 +240,13 @@ class OC_User {
 	 * Checks if the user is logged in
 	 */
 	public static function isLoggedIn(){
-		if( isset($_SESSION['user_id']) AND $_SESSION['user_id'] AND self::userExists($_SESSION['user_id']) ){
-			return true;
-		}
-		else{
-			return false;
+		if( isset($_SESSION['user_id']) AND $_SESSION['user_id']) {
+			OC_App::loadApps(array('authentication'));
+			if (self::userExists($_SESSION['user_id']) ){
+				return true;
+			}
 		}
+		return false;
 	}
 
 	/**
@@ -331,11 +330,9 @@ class OC_User {
 	public static function getUsers(){
 		$users=array();
 		foreach(self::$_usedBackends as $backend){
-			if($backend->implementsActions(OC_USER_BACKEND_GET_USERS)){
-				$backendUsers=$backend->getUsers();
-				if(is_array($backendUsers)){
-					$users=array_merge($users,$backendUsers);
-				}
+			$backendUsers=$backend->getUsers();
+			if(is_array($backendUsers)){
+				$users=array_merge($users,$backendUsers);
 			}
 		}
 		asort($users);
@@ -349,11 +346,9 @@ class OC_User {
 	 */
 	public static function userExists($uid){
 		foreach(self::$_usedBackends as $backend){
-			if($backend->implementsActions(OC_USER_BACKEND_USER_EXISTS)){
-				$result=$backend->userExists($uid);
-				if($result===true){
-					return true;
-				}
+			$result=$backend->userExists($uid);
+			if($result===true){
+				return true;
 			}
 		}
 		return false;
diff --git a/lib/user/backend.php b/lib/user/backend.php
index c31d4b5785b..be068a63ce0 100644
--- a/lib/user/backend.php
+++ b/lib/user/backend.php
@@ -32,11 +32,8 @@ define('OC_USER_BACKEND_NOT_IMPLEMENTED',   -501);
  * actions that user backends can define
  */
 define('OC_USER_BACKEND_CREATE_USER',       0x000001);
-define('OC_USER_BACKEND_DELETE_USER',       0x000010);
-define('OC_USER_BACKEND_SET_PASSWORD',      0x000100);
-define('OC_USER_BACKEND_CHECK_PASSWORD',    0x001000);
-define('OC_USER_BACKEND_GET_USERS',         0x010000);
-define('OC_USER_BACKEND_USER_EXISTS',       0x100000);
+define('OC_USER_BACKEND_SET_PASSWORD',      0x000010);
+define('OC_USER_BACKEND_CHECK_PASSWORD',    0x000100);
 
 
 /**
@@ -49,11 +46,8 @@ abstract class OC_User_Backend {
 
 	protected $possibleActions = array(
 		OC_USER_BACKEND_CREATE_USER => 'createUser',
-		OC_USER_BACKEND_DELETE_USER => 'deleteUser',
 		OC_USER_BACKEND_SET_PASSWORD => 'setPassword',
 		OC_USER_BACKEND_CHECK_PASSWORD => 'checkPassword',
-		OC_USER_BACKEND_GET_USERS => 'getUsers',
-		OC_USER_BACKEND_USER_EXISTS => 'userExists'
 	);
 
 	/**
@@ -85,4 +79,34 @@ abstract class OC_User_Backend {
 	public function implementsActions($actions){
 		return (bool)($this->getSupportedActions() & $actions);
 	}
+
+	/**
+	* @brief delete a user
+	* @param $uid The username of the user to delete
+	* @returns true/false
+	*
+	* Deletes a user
+	*/
+	public function deleteUser( $uid ){
+		return false;
+	}
+
+	/**
+	* @brief Get a list of all users
+	* @returns array with all uids
+	*
+	* Get a list of all users.
+	*/
+	public function getUsers(){
+		return array();
+	}
+
+	/**
+	* @brief check if a user exists
+	* @param string $uid the username
+	* @return boolean
+	*/
+	public function userExists($uid){
+		return false;
+	}
 }
diff --git a/lib/user/example.php b/lib/user/example.php
index 18bc6bce00d..7f3fd1b8578 100644
--- a/lib/user/example.php
+++ b/lib/user/example.php
@@ -40,17 +40,6 @@ abstract class OC_User_Example extends OC_User_Backend {
 	}
 
 	/**
-		* @brief delete a user
-		* @param $uid The username of the user to delete
-		* @returns true/false
-		*
-		* Deletes a user
-		*/
-	public function deleteUser( $uid ){
-		return OC_USER_BACKEND_NOT_IMPLEMENTED;
-	}
-
-	/**
 		* @brief Set password
 		* @param $uid The username
 		* @param $password The new password
@@ -74,23 +63,4 @@ abstract class OC_User_Example extends OC_User_Backend {
 	public function checkPassword($uid, $password){
 		return OC_USER_BACKEND_NOT_IMPLEMENTED;
 	}
-
-	/**
-		* @brief Get a list of all users
-		* @returns array with all uids
-		*
-		* Get a list of all users.
-		*/
-	public function getUsers(){
-		return OC_USER_BACKEND_NOT_IMPLEMENTED;
-	}
-
-	/**
-		* @brief check if a user exists
-		* @param string $uid the username
-		* @return boolean
-		*/
-	public function userExists($uid){
-		return OC_USER_BACKEND_NOT_IMPLEMENTED;
-	}
 }
diff --git a/lib/util.php b/lib/util.php
index fda60587b82..20888fa71f4 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -10,6 +10,8 @@ class OC_Util {
 	public static $headers=array();
 	private static $rootMounted=false;
 	private static $fsSetup=false;
+	public static $core_styles=array();
+	public static $core_scripts=array();
 
 	// Can be set up
 	public static function setupFS( $user = "", $root = "files" ){// configure the initial filesystem based on the configuration
@@ -29,7 +31,7 @@ class OC_Util {
 		}
 		
 		// Check if apps folder is writable.
-		if(!is_writable(OC::$SERVERROOT."/apps/")) {
+		if(OC_Config::getValue('writable_appsdir', true) && !is_writable(OC::$SERVERROOT."/apps/")) {
 			$tmpl = new OC_Template( '', 'error', 'guest' );
 			$tmpl->assign('errors',array(1=>array('error'=>"Can't write into apps directory 'apps'",'hint'=>"You can usually fix this by giving the webserver user write access to the config directory in owncloud")));
 			$tmpl->printPage();
@@ -39,7 +41,7 @@ class OC_Util {
 		// Create root dir.
 		if(!is_dir($CONFIG_DATADIRECTORY_ROOT)){
 			$success=@mkdir($CONFIG_DATADIRECTORY_ROOT);
-            if(!$success) {
+			if(!$success) {
 				$tmpl = new OC_Template( '', 'error', 'guest' );
 				$tmpl->assign('errors',array(1=>array('error'=>"Can't create data directory (".$CONFIG_DATADIRECTORY_ROOT.")",'hint'=>"You can usually fix this by giving the webserver write access to the ownCloud directory '".OC::$SERVERROOT."' (in a terminal, use the command 'chown -R www-data:www-data /path/to/your/owncloud/install/data' ")));
 				$tmpl->printPage();
@@ -58,7 +60,6 @@ class OC_Util {
 			self::$rootMounted=true;
 		}
 		if( $user != "" ){ //if we aren't logged in, there is no use to set up the filesystem
-
 			OC::$CONFIG_DATADIRECTORY = $CONFIG_DATADIRECTORY_ROOT."/$user/$root";
 			if( !is_dir( OC::$CONFIG_DATADIRECTORY )){
 				mkdir( OC::$CONFIG_DATADIRECTORY, 0755, true );
@@ -329,4 +330,17 @@ class OC_Util {
 		}
 		exit();
 	}
+
+	/**
+	 * get an id unqiue for this instance
+	 * @return string
+	 */
+	public static function getInstanceId(){
+		$id=OC_Config::getValue('instanceid',null);
+		if(is_null($id)){
+			$id=uniqid();
+			OC_Config::setValue('instanceid',$id);
+		}
+		return $id;
+	}
 }