Make Rugged::Commit#diff return a diff against its parent by default.
Make Rugged::Commit#diff return a diff against its parent by default.

tpickett66/rugged,libgit2/rugged,Acidburn0zzz/rugged,Acidburn0zzz/rugged,tpickett66/rugged,saraid/rugged,saraid/rugged,libgit2/rugged,tpickett66/rugged,Acidburn0zzz/rugged,saraid/rugged,libgit2/rugged