Links to filestore items now download file with correct filename and extension

+ View and Raw both download the actual file
+ Blame will show the metafile

Fix for #976 - Filestore links via browser

Ticket #998 document dh keysize

Fix char encoding in setup_proxy.mkd

Fix authentication failure warning log messages for FEDERATION_USER

Lower log level of servlet authenticate when request is already authenticated

Fix for #993 LIST_BRANCHES without admin

Replaced the canAccess() method in RpcFilter with !adminRequest,
that should solve the problem.

When calling a servlet which has already been authenticated, the server would produce
a lot of superfluous log entries, e.g:

Called servlet authenticate when request is already authenticated.

The log level for this log entry has been lowered down to DEBUG.

The AuthenticationManager did not encounter for FEDERATION_USER and would unnecessarily
generate a lot of failure warning log messages, e.g:

Failed login attempt for $gitblit, invalid credentials from XXX.XX.XX.XX

A simple condition will prematurely return null bypassing the regular authentication path
and immediately make the authentication be routed via FederationManager.

+ GitLFS client support
+ FilestoreModel now parses meta file
+ Read meta heading from cache if available
+ Authentication based on accept headers for browser view filestore login
+ PathModel & PathChangeModel now understands filestore items
+ Zip & Rar downloads contain include filestore items
+ Filestore servlet returns LFS JSON error only if accepted by client
+ DiffStat now knows repository to allow identification of filestore items
+ Filestore items identified and returned via view, raw & blob links on
blame, commitDiff, commit and Tree pages

Change Jenkins groovy script for any protocol (git/http/ssh)

groovy.jenkinsGitbaseurl in gitblit.properties or web.xml can
override the http default protocol

Refactor authentication for servlet HTTP header handler

Log username with access logging

fix for #978 - HTML5 date input support

revise logic for forcing dotfile to text

+ JS patch/hack to coerce legacy wicket into talking to a HTML5 input type
+ JS script to hide inline help on date format when using HTML5 date picker
  + Date picker shown in user locale and standard does not support custom
  format.
  + Always sent in ISO8601 format

This was unused and causing provider lookup to fail in
AuthenticationManager.findProvider() by changing it out
from underneath. As a result, the supportXChanges methods
weren't being reported correctly.

Remove empty catch blocks to stop swallowing exceptions. #498

fix for #967 filestore menu and help

+ Filestore listing filtered by user view permissions
+ Configuration help for filestore relocated to website files
+ Added migration example

fix for #968 extracting repository from URI

+ Allows using lfs when `server.contextPath = /git`

This was originally from https://github.com/gitblit/gitblit/pull/950 but seems to have been reverted when develop branch was merged with master.