gen-openbsd-tags.sh synchronizes local tags from the portable tree with
the openbsd git mirror. It does this by matching commit timestamps,
which can handle rehashing due to modifications of the git import scope
if we need it later.
check-release.sh generates a release tarball and compares it to an
actual release. This has shown a few mistakes in past release, but we
can use it to ensure are no issues with future releases.