(getfiles): Just return readdir results, don't strip . and .. and

(getfiles): Just return readdir results, don't strip . and .. and
don't return absolute paths.  We walk the file list enough times
already, there's no need to walk it for this.

(filter_mail): Skip . and .. in the @msglist.

(MAIN): Instead of passing getfiles $MAILDIR/new, chdir there and pass '.'.