1. Don't rely on the current attempt, make caller calculate total.
2. Save preimage inside attempt, for slow mode.
3. Hoist it higher in the file.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Any file in this directory which is executable and whose name only
consists of alphanumeric characters, space, '.', '-' or '_' will be
automatically loaded when lightningd starts (unless suppressed with
commandline options).
db1e26eb67