1. htlc->fail has been changed to a u8 *.
2. wallet_get_newindex saves to the db.
3. peer->next_htlc_id is saved to the db in peer_save_commitsig_sent() below.
4. We do store commit in peer_save_commitsig_received(peer, commitnum),
and the fixme below talks about HTLC sigs.
5. We do commit shachain and next_per_commit_point in wallet_shachain_add_hash
and update_per_commit_point respectively.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>