This was originally done as part of the bookkeeper introduction, but it deserves its
own patch (and that one didn't remove the bitcoin/chainparams.o from the individual
requirements lines).
Suggested-by: @niftynei
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
There's two situations where we're missing info.
One is we get a 'channel_closed' event (but there's no 'channel_open')
The other is a balance_snapshot arrives with information about accounts
that doesn't match what's already on disk. (For some of these cases, we
may be missing 'channel_open' events..)
In the easy case (no channel_open missing), we just figure out what the