scripts: break tests down from type structure
scripts: switch to failing to classification tests
scripts: fix classification logic
tests: remove unused import
scripts: recursive scriptHash no longer problematic
scripts: add missing test data
opcodes: prefer OP_0
Script: adds toASM/fromASM
tests: avoid pointless toASM in description
scripts: add falsy classifications and fix multisig
Transaction: remove signing operations
txbuilder stuff