Add the various pillowfight changes to the release notes

Change-Id: I0f520907da7558f6bc7b1c31495284c76793937d
Reviewed-on: http://review.couchbase.org/42133
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>