These changes decode valid SIGHASH types on signatures in assembly (asm) representations of scriptSig scripts.
This squashed commit incorporates substantial helpful feedback from jtimon, laanwj, and sipa.
CTransAction::IsEquivalentTo was introduced in #5881.
This functionality is only useful to the wallet, and should never have
been added to the primitive transaction type.
Define CTransaction::IsEquivalentTo(const CTransaction& tx)
True if only scriptSigs are different. In other words, true if
the two transactions are malleability clones. In other words,
true if the two transactions have the same effect on the
outside universe.
In the wallet, only SyncMetaData for equivalent transactions.
