Improve error handling in repo_new_with_backend
Improve error handling in repo_new_with_backend

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