Add comments explaining changed semantics of pow_tests
Add comments explaining changed semantics of pow_tests

CTRoundTable/Encrypted.Cash,bitcoinsSG/zcash,bitcoinsSG/zcash,CTRoundTable/Encrypted.Cash,bitcoinsSG/zcash,CTRoundTable/Encrypted.Cash,bitcoinsSG/zcash,bitcoinsSG/zcash,CTRoundTable/Encrypted.Cash,CTRoundTable/Encrypted.Cash,CTRoundTable/Encrypted.Cash,bitcoinsSG/zcash