Fix undisposed stream in test
Refactor git_branch_iterator
Introduce Proxy.git_iterator
Add Configuration.Find(regexp)
Remove unnecessary global config check
Introduce repo.Committish(es)
Introduce Repository.Blame
Publicize Configuration.BuildSignature()
Configuration.Testability++
Fix off-by-one error in BlameHunk debugger display
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.

This is a work in progress, as the native method calls are not yet
implemented.
Implemented remote_get_fetch/push_refspecs native methods
Fixed property type of Push/FetchRefSpecs
Added test to update push/fetch refspecs
Implemented native methods git_remote_set_push/fetch_refspecs
Added more tests
Added FetchRefSpecs/PushRefSpecs properties to Remote
Removed unused "using" directives
Added missing blank lines in NativeMethods