Makefile: Delete 1.11.x editor *.map.cfg WML files on clean target

I'm not going to use the editor WML features, but since it's writing WML
files for everything anyway I might as well have a simple way to get rid
of it so I can use the 1.11.x editor without worrying about garbage
lying around.
Exclude *.map.cfg files from add-on uploads and git status