The old MAKE_SNAPSHOT.sh and MAKE_RELEASE.sh scripts created tarballs
that could be uploaded to icarus.com and SourceForge. Now we release
on GitHub, we need to make all the necessary changes in the git
repository, temporarily creating a release_tag.h file and deleting it
after we have created the snapshot or release tag. This allows GitHub
to automatically generate the tarballs for us.
Martin Whitaker