[Sharing 2.0] Add a new db column for the file owner

We need to store the owner of a file in the db to do efficient queries
on the owner of a file. Without this we need to construct fill paths for
each file id in the table and see who the owner of a file is. Which does
not scale.

db_structure.xml

@@ -684,6 +684,7 @@
 			</field>
 
 			<!-- Foreign Key users::uid -->
+            <!-- This is the initiator of the share -->
 			<field>
 				<name>uid_owner</name>
 				<type>text</type>
@@ -692,6 +693,19 @@
 				<length>64</length>
 			</field>
 
+			<!-- Foreign Key users::uid -->
+            <!-- This is the owner of the file, this can be
+                 different from the initiator of the share.
+                 The naming is subobtimal but prevents huge
+                 migration steps -->
+			<field>
+				<name>uid_fileowner</name>
+				<type>text</type>
+				<default></default>
+				<notnull>false</notnull>
+				<length>64</length>
+			</field>
+
 			<!-- Foreign Key share::id or NULL -->
 			<field>
 				<name>parent</name>

version.php

@@ -25,7 +25,7 @@
 // We only can count up. The 4. digit is only for the internal patchlevel to trigger DB upgrades
 // between betas, final and RCs. This is _not_ the public version number. Reset minor/patchlevel
 // when updating major/minor version number.
-$OC_Version = array(9, 0, 0, 2);
+$OC_Version = array(9, 0, 0, 3);
 
 // The human readable string
 $OC_VersionString = '9.0 pre alpha';