There's a few structs/wire calls that only exist under experimental features.
These were in a common file that was shared/used a bunch of places but
this causes problems. Here we move one of the problematic methods back
into `openingd`, as it's only used locally and then isolate the
references to the `witness_stack` in a new `common/psbt_internal` file.
This lets us remove the iff EXP_FEATURES inclusion switches in most of
the Makefiles.
We can use a fixed value and close the channel if they don't cover their
amount; this wasn't really helping with anything other than setting a
floor for an expected feerate
Greatly simplify the changeset API. Instead of 'diff' we simply generate
the changes.
Also pulls up the 'next message' method, as at some point the
interactive tx protocol will be used for other things as well
(splices/closes etc)
Suggested-By: @rustyrussell
includes facilities for
- sorting psbt inputs by serial_id
- sorting psbt outputs by serial_id
- adding a serial_id
- getting a serial_id
- finding the diffset between two psbts
- adding a max_len to a psbt input
- getting a max_len from a psbt input
