Change-Id: I5f0f50f4ae7d332e9f724a2e6f074fa71f646035

This is the first step towards modularization and injection.  All
direct references to the GitBlit singleton within the Wicket pages
and panels have been replaced to proxy methods in the GitBlitWebApp
singleton.  There are still two Wicket classes which rely on the
GitBlit singleton; those require manual instantiation (servlet 3).

Change-Id: I0cdbbcf87959d590c446c99abb09c07c87c737bc

The mirror executor will fetch ref updates for repository mirrors.  This
feature is disabled by default and can be enabled by setting
git.enableMirroring=true.  The period between update checks is
configurable, but it is global.  An individual rpeository may not set
it's own update schedule.

Requirements:
1. you must manually clone the repository using native git
   git clone --mirror git://somewhere.com/myrepo.git
2. the "origin" remote must be the mirror source
3. the "origin" repository must be accessible without authentication OR
   the credentials must be embedded in the origin url (not recommended)

Notes:
1. "origin" SSH urls are untested and not likely to work
2. mirrors cloned while Gitblit is running are likely to require
   clearing the gitblit cache (link on the repositories page of an
   administrator account)
3. Gitblit will automatically repair any invalid fetch refspecs with a
   "//" sequence.

Change-Id: I4bbe3fb2df106366ae4c2313596d0fab0dfcac46

Change-Id: I422696130695cb18d4c1518b0d53265d7247f966

Change-Id: Idb7de272589e086da9b2b3a241dcd082c1c8f27b

Renamed pushlog to reflog to better match it's current and future purpose.
Split PushesPanel into ReflogPanel and DigestsPanel.
Overhauled project pages and gave them a coherent purpose from the dashboard.

This will probably be refined some more to merge the http/https and git urls
into a single url panel.

This is a massive commit which reorganizes the entire project structure
(although it is still monolithic), removes the Build classes, and
switches to Moxie, a smarter Ant build tookit based on the original
Gitblit Build classes.

The Ant build script will likely require additional fine-tuning, but
this is big step forward.

The fork mechanism clones the repository , access restrictions, and
other config options.  The app has been updated throughout to handle
personal repositories and to properly display origin/fork links.

In order to fork a repository the user account must have the #fork role,
the origin repository must permit forking, and the user account must
have standard clone permissions to the repository.

Because forking introduces a new user role no existing user accounts can
automatically begin forking a repository.  This is both a pro and a con.

Since the fork has the same access restrictions as the origin repository,
those who can access the origin may also access the fork.  This is intentional
to facilitate integration-manager workflow.  The fork owner does have the
power to completely change the access restrictions of his/her fork.