Introduce repo.Committish(es)
Introduce Repository.Blame
Publicize Configuration.BuildSignature()
Configuration.Testability++
Fix off-by-one error in BlameHunk debugger display
fix spell mistake for argument pre-inspection.

this is a tiny modification for spell mistake.
orig:
Ensure.ArgumentNotNullOrEmptyString(thirdKeyPart, "secondKeyPart");
now:
Ensure.ArgumentNotNullOrEmptyString(thirdKeyPart, "thirdKeyPart");
Add debugger display for RefSpec
Extended RemoteUpdater to update refspecs

Push/Pull Ref Specs can be updated via Remotes.Update(). The collections
can either be manipulated or replaced completely. Any changes are saved
immediately.
Update libgit2 to 96fb6a6

https://github.com/libgit2/libgit2/compare/98eaf39...96fb6a6
Initial rename detection work
Revise API for rename/copy detection