JGit 4.0.0 fixes a memory leak but introduces a non-compatible change
for closing the RevWalk: before it was release() but now is close()

Empty folders are automatically skipped when browsing repository tree  (similar to github "folder jumping" feature).

This uses a new 'ot' request parameter to indicate the object type of the content to return, which can be ither TAG or COMMIT.
If this is not provided, then COMMIT is assumed to maintain backwards compatability.
If tags are returned, then the paging parameters, 'l' and 'pg' are still supported, but searching options are currently ignored.

A basic issue tracker styled as a hybrid of GitHub and BitBucket issues.
You may attach commits to an existing ticket or you can push a single
commit to create a *proposal* ticket.

Tickets keep track of patchsets (one or more commits) and allow patchset
rewriting (rebase, amend, squash) by detecing the non-fast-forward
update and assigning a new patchset number to the new commits.

Ticket tracker
--------------

The ticket tracker stores tickets as an append-only journal of changes.
The journals are deserialized and a ticket is built by applying the
journal entries.  Tickets are indexed using Apache Lucene and all
queries and searches are executed against this Lucene index.

There is one trade-off to this persistence design: user attributions are
non-relational.

What does that mean?  Each journal entry stores the username of the
author.  If the username changes in the user service, the journal entry
will not reflect that change because the values are hard-coded.

Here are a few reasons/justifications for this design choice:

1. commit identifications (author, committer, tagger) are non-relational
2. maintains the KISS principle
3. your favorite text editor can still be your administration tool

Persistence Choices
-------------------

**FileTicketService**: stores journals on the filesystem
**BranchTicketService**: stores journals on an orphan branch
**RedisTicketService**: stores journals in a Redis key-value datastore

It should be relatively straight-forward to develop other backends
(MongoDB, etc) as long as the journal design is preserved.

Pushing Commits
---------------

Each push to a ticket is identified as a patchset revision.  A patchset
revision may add commits to the patchset (fast-forward) OR a patchset
revision may rewrite history (rebase, squash, rebase+squash, or amend).
Patchset authors should not be afraid to polish, revise, and rewrite
their code before merging into the proposed branch.

Gitblit will create one ref for each patchset.  These refs are updated
for fast-forward pushes or created for rewrites.  They are formatted as
`refs/tickets/{shard}/{id}/{patchset}`.  The *shard*  is the last two
digits of the id.  If the id < 10, prefix a 0.  The *shard* is always
two digits long.  The shard's purpose is to ensure Gitblit doesn't
exceed any filesystem directory limits for file creation.

**Creating a Proposal Ticket**

You may create a new change proposal ticket just by pushing a **single
commit** to `refs/for/{branch}` where branch is the proposed integration
branch OR `refs/for/new` or `refs/for/default` which both will use the
default repository branch.

    git push origin HEAD:refs/for/new

**Updating a Patchset**

The safe way to update an existing patchset is to push to the patchset
ref.

    git push origin HEAD:refs/heads/ticket/{id}

This ensures you do not accidentally create a new patchset in the event
that the patchset was updated after you last pulled.

The not-so-safe way to update an existing patchset is to push using the
magic ref.

    git push origin HEAD:refs/for/{id}

This push ref will update an exisitng patchset OR create a new patchset
if the update is non-fast-forward.

**Rebasing, Squashing, Amending**

Gitblit makes rebasing, squashing, and amending patchsets easy.

Normally, pushing a non-fast-forward update would require rewind (RW+)
repository permissions.  Gitblit provides a magic ref which will allow
ticket participants to rewrite a ticket patchset as long as the ticket
is open.

    git push origin HEAD:refs/for/{id}

Pushing changes to this ref allows the patchset authors to rebase,
squash, or amend the patchset commits without requiring client-side use
of the *--force* flag on push AND without requiring RW+ permission to
the repository.  Since each patchset is tracked with a ref it is easy to
recover from accidental non-fast-forward updates.

Features
--------

- Ticket tracker with status changes and responsible assignments
- Patchset revision scoring mechanism
- Update/Rewrite patchset handling
- Close-on-push detection
- Server-side Merge button for simple merges
- Comments with Markdown syntax support
- Rich mail notifications
- Voting
- Mentions
- Watch lists
- Querying
- Searches
- Partial miletones support
- Multiple backend options

Change-Id: I7f8ad8936e620dd06e88d85f6837248eea75a1ec

Change-Id: I0da34a1da0dc3dcb07a98629c2284184402cb23a

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: I19f9507fdb859902a6df96f1960433a91378e400

Change-Id: I9f91138b20219be6e3c4b28251487df262bff6cc

Change-Id: I8f26746a611e9ab955efe8b2597cc81db48fb085

This is a normal condition that complicates debugging, i.e.
when catching all NPE's.

Implement adjusting file and directory permissions for shared
repositories in JGitUtils.

Implement the methods getFilemode and setFilemode
in JnaUtils. Not using the libc names as we don't
necessarily use JNA and because it is not necessarily
a one to one mapping.

repository as if it was created with the --shared command line switch of git.

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.

DisplayName used previously contained ONLY the last part
of ref-spec: this would have not worked when looking for 
objects with full ref-spec.

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.