change locate to use relglobs by default
This makes its default behaviour useful again (
issue108), and
changes it search the entire repository by default (instead
of just the cwd), just like all other commands.
It also hides
issue204 by default, but you'll still see the
same behaviour if you give it a relpath: pattern.
localrepo.walk: if we're walking a specific revision, sort the files
This is more consistent with our behaviour while walking the working directory.