- For when IWADs are too specific, filter by the base gametype too.
- Minor small edits to the sndinfo.txt files so that zipdir will notice
the changes, since it doesn't check path names when checking for
file differences.
- This means the original need for $ifdoom, $ifheretic, etc directives is
no more, but they need to stay for compatibility with third-party wads
that use them.