c7c553ebc0 Remove impossible InvalidParity error variant (Martin Habovstiak)
Pull request description:
Since we do `& 1`, only 0 and 1 are possible values, so the error return there can never happen. I made this explicit by manually setting the parity.
This is a rebase of Steven's change #2163 with a rewrite of `match` to not panic.
ACKs for top commit:
tcharding:
ACK c7c553ebc0
apoelstra:
ACK c7c553ebc0
Tree-SHA512: 5591fda686295f330b6da757a0052687eddec135ac947a2801343f1681bc4fd9f6cfb722ac1339ae6187a8784e7629b5f12cca32b33a81ffc8791b4407b29f85