Buildbot Keyring

Hi.

I've created a Buildbot keyring: it's a file containing PGP public keys of people that can release source/binary packages. The only person I couldn't find public key is @bdbaddog. I've sent a letter to him but got no response. Once I get his public key, I'll update the keyring.

I'm going to point at this file in some places on trac wiki.