This is a bit tricky: for our signing code, we don't want scriptsigs,
but to calculate the txid, we need them. For most transactions in lightning,
they're pure segwit so it doesn't matter, but funding transactions can
have P2SH-wrapped P2WPKH inputs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
built_utxos needs to calculate fees for figuring out how many utxos to
use, so fix that logic and rely on it.
We make build_utxos return a pointer array, so funding_tx can simply hand
that to permute_inputs.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The signing helper was really just for testing, so remove it. But
turn the funding_tx() function into a useful one by making it take the
utxo array.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
