Add Objective Git submodule and subproject
Start using GTRepository
Reorder project files
More Objective Git/libgit2 usage

checkout, parseSymbolicReference, unstaged files
Remove 10.8-only call
Fix for displaying merge commits
Update RBSplitView
Checkout fix
ObjGit replacement for parseReference

parseReference was only ever used to see if HEAD exists, so that's what the replacement does.
Update Objective Git
Use FullHeightToolbar for status view
Merge branch 'refs/heads/objgit'

Conflicts:
	.gitmodules
	Xit.xcodeproj/project.pbxproj
Use stageFile: instead of addFile:. They were the same!
Just have one commit method
Don't use @public
Add isWriting property and writes: parameter
ObjGit read staged files
Write lock test

Fixed error reporting for some functions.
Some others converted to libgit2 because git sometimes returns 1 on success.
Disable writing commands when repo is writing
Merge branch 'refs/heads/lock'

Conflicts:
	Xit/XTRepository+Parsing.m