This is an empty commit, in that no files are being changed.  This
commit is just here to leave a message, which is that I am revoking my
current signing key:

Signature key ....: F0C1 EF27 14C5 0582 915C  59F8 14A7 B2A5 6335 B8D5
      created ....: 2015-12-13 06:54:47

Today (Sunday, October 22, 2017) will be the last day I sign anything
with the above key.

I am revoking this key because of CVE-2017-15361.  My signing key was
generated by, and lives on, a Yubikey 4 that is affected by the
vulnerability described in the CVE.  Once the details of the
vulnerability are out, it will be possible for others to get my
signing private key.

This affects all of my signed commits and tags.  Although re-signing
the tags is possible (which I will do once I have a new key),
re-signing commits is not really possible, because that would cause
the commit ID to change, affecting the rest of the tree, and making it
really hard for other people.

So, I am leaving this note.  By leaving this note, I make a new commit
ID.  Once I have my new key, I will leave another note, which says
that this commit ID is valid.  That makes kind of a chain of trust,
even though it's likely that Git will say the signature of this note
is invalid.

Not only that, but every commit after this one will make it harder for
someone to go back and change the note: The more commits there are
after this note, the more commit IDs will change if this node is
modified; and the more people who have clones of this repo, the bigger
the commit difference will be when they do a pull.  Of course, it's
not perfect, but I think it's better than nothing!

Maybe there will be a future way to re-sign commits, in a way that
does not disrupt the repository.

For reference, here are all of my current tags, and their commit IDs:

release/1 b5c5912a
release/2 69fe86f0