reserveinputs marks UTXOs reserved for 12 hours, so we won't select them
for spending: unreserveinputs marks them available again.
Exposes param_psbt() for wider use.
Disabled the test_sign_and_send_psbt since we're altering the API;
the final patch restores it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It looked like we weren't printing the address on closing outputs.
But we are, because the 'scriptPubkey' field is in the 'outputs' db
table since 0.7.3 (66a47d2761).
So make the logic clearer, and remove a completely bogus comment (UTXOs
with closing_info are definitely spendable!).
We export the json_add_utxos() for future use, too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>