Jack D

Had troubles with `make` step when building on any version of node after 8. I had to `nvm use 8` to get it to work.

Unchained plans to support p2wsh using the same `m/45` path we use for p2sh. This change adds the `UNCHAINED_` patterns to bitcoin `InputScriptType.SPENDP2SHWITNESS`.

BIP174: Specify PSBT_IN_PREVIOUS_TXID serialization order

2

This change updates descriptions for the `PSBT_IN_PREVIOUS_TXID` field to specify serialization order. It was not straightforward the order with which to store the txid in a psbt. It's not clearly...