We're about to allow changes while we're waiting for a commit ack.
This means we can't have a single "unacked changes" queue; when we
receive the revocation reply, we need to apply the unacked changes
known at the time we sent the commit, not any we've created since
then.
Note that we still only have a single staged_commit; we never have two
outstanding commits, since for simplicity we will still block
following update_commit pending the reply to the current one.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
d4862938c8