++libgit2
update GTTreeBuilder for new libgit2.
New status options.
transfer callback no longer called on local clones.

it seems.
Bump libgit2
Merge remote-tracking branch 'origin/master' into bump_libgit_for_permissions

Conflicts:
	External/libgit2
++libgit2
Merge remote-tracking branch 'origin/master' into bump_libgit_for_permissions

Conflicts:
	Classes/GTTreeBuilder.h
	External/libgit2
++libgit2
++libgit2
Compile this file maybe?
Merge remote-tracking branch 'origin/master' into bump_libgit_for_permissions

Conflicts:
	ObjectiveGitFramework.xcodeproj/project.pbxproj
Revert "transfer callback no longer called on local clones."

This reverts commit 3536751bc37ba1f0705ce29447e801eba8c0a1c0.
Merge pull request #372 from libgit2/bump_libgit_for_permissions

Bump libgit for the unreadable files fix.