Fix a bug during `rcfiles save` w/untracked files
Fix a bug during `rcfiles save` w/untracked files

Untracked files weren't saving properly because the new `__git` method
returns full output, not individual lines, so anything more than one new
untracked file, and no new untracked files would be added to the commit.

sycobuny/rcfiles,sycobuny/rcfiles