Add a release checklist.
Add a release checklist.

I always forget things, this is good documentation, and it's been
helpful with the opus releases.


git-svn-id: 03f0f1727258f1959b7b485b30a676bafdb78148@19461 0101bb08-14d6-0310-b084-bc0e0c8e3800

ShiftMediaProject/vorbis,libninjam/libvorbis,ShiftMediaProject/vorbis,ShiftMediaProject/vorbis,brion/vorbis,ShiftMediaProject/vorbis,libninjam/libvorbis,ShiftMediaProject/vorbis,libninjam/libvorbis,ShiftMediaProject/vorbis,brion/vorbis,brion/vorbis,brion/vorbis,libninjam/libvorbis