Allow heirs to produce an OP_RETURN output instead of a regular BTC
payment. An address prefixed with OP_RETURN: carries hex data (max 80
bytes); such heirs always have amount 0 and are excluded from amount
calculations. GUI dialog shows a message field with the decoded text,
the heir list displays the decoded message, and the OP_RETURN output
is emitted with zero value in inheritance transactions.
svatantrya
649910e599
