To do this we keep an order counter so we know how to retransmit. We
could simply keep old packets, but this is a little clearer for now.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We want to stop keeping old commitment information (except the minimal
txid to commitment-number mapping). One place we currently use it is
after sending a commitment signature, and before we've received the
revocation for the old commitment. For this duration, there are two
valid commitment transactions.
So we store "their_prev_revocation_hash" explicitly for this duration.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
