0f74eb6876 Remove the unused crate::Error (Tobin C. Harding)
74154c2294 Add block::ValidationError (Tobin C. Harding)
3a9b5526b3 Move BlockHash From impls (Tobin C. Harding)
Pull request description:
Remove the `crate::Error` and replace its usage with `block::ValidationError`.
ACKs for top commit:
apoelstra:
ACK 0f74eb6876
Kixunil:
ACK 0f74eb6876
Tree-SHA512: 80b2c98d3d8f7c3f060c8ea2d94e1ebe118c07d0dcf91f6d13aed00df2cb0b15bf5e295ec0976d88d81e029cf7d3e8e4a1fe70120db57e49bbd8dd229291836b