b873a3cd44 Do infallible int from hex conversions (Tobin C. Harding)
4d762cb08c Remove the FromHexStr trait (Tobin C. Harding)
026537807f Remove mention of packed (Tobin C. Harding)
Pull request description:
The `FromHexStr` trait is used to parse integer-like types, however we can achieve the same using inherent methods.
Move the hex parsing functionality to inherent methods, keeping the same behaviour in regard to the `0x` prefix.
Patch 1 is trivial preparatory cleanup.
ACKs for top commit:
apoelstra:
ACK b873a3cd44
sanket1729:
ACK b873a3cd44
Tree-SHA512: a280169b68304fcc1a531cc9ffb6914b70238efc4c2241a766105053911a373a0334b73e5ea3525c331ccb81ce98c43fea96dae77668804e608376a48d5ed8ac