v0.47

 - Added support for Notes (GH#144)
 - Stash -> save() now returns a Commit object (GH#145) (Incompatible change)
 - Stash -> foreach()'s callback now receives a Commit object instead of the
   object id (GH#145) (Incompatible change)
 - Added Index methods (Beta) (GH#146):
    + add_conflict
    + get_conflict
    + merge
 - Added Index::Entry methods (Beta) (GH#146):
    + clone
 - Added Merge::File::Result methods (Beta) (GH#146):
    + automergeable
    + content
    + path
 - The supported authentication types are now supplied to the Remote's
   credentials callback.
 - Update libgit2 to 4c53489 (GH#147)
 - Removed Remote methods (GH#147) (Incompatible change):
    + check_cert()
 - Added Remote certificate callback (GH#148)