Fix 'undefined' committer issue
Fix missing `[super init]` in PBGitRef
Hide the storage of PBGitRef.ref
Use Objective-Git to check ref validity

Continuing work on issue #2
Fix bug in `- [PBGitRepository addRef:]` with symbolic refs showing the wrong name
Watch both the index and working directories

#244
Major refactor of PBGitRepositoryWatcher

This separates the FS event handling for the 'git' and 'working' directories; and fixes several bugs along the way.

#244
Fix Archive build action
Xcode update
Update all XIBs to target OS X 10.7 deployment
Handle ignored files better
Fix JS for refactored property ivar
Use Monaco for displaying SHAs in the history and commit views
Fix tracking branch lookup
Disable 'delete' ref menu item for remote branches

It didn't actually perform the remote delete, just dropped the local copy of the ref.
Don't allow deleting the head (checked out) ref

Closes #240
Enable ⌘(F)(G)(ꜛG), to find in commit list
Enable alternate-row highlighting in commit list
Merge branch 'highlighting'
Fix off-by-one retina icons: detail view