Signed tags in octopus merge..

Just a heads-up and congrats: octopus merges of signed tags work well,
and did exactly the RightThing(tm), both at merge time and with
"--show-signature".

I knew it was supposed to work, but I have to admit that I was a bit
apprehensive about it when I tried.

Current top-of-head (commit 81d48f0aee54) in the kernel, in case you care.

Good job,

                 Linus