06afd52a12 Improve hashes::Error (Tobin C. Harding)
Pull request description:
We are trying to make error types stable on the way to v1.0
The current `hashes::Error` is a "general" enum error type with a single variant, better to use a struct and make the error usecase specific.
Improve the `hashes::Error` by doing:
- Make it a struct
- Rename to `FromSliceError`
- Move it to the crate root (remove `error` module)
Includes usage in `bitcoin`.
ACKs for top commit:
apoelstra:
ACK 06afd52a12
Kixunil:
ACK 06afd52a12
Tree-SHA512: 20a517daaf3e9e09744e2a65cde6e238c8f2d1224899a6c04142a3a4e635d54112b0a2e846d25256071bb27cb70f7482380f98e9a535a5498aa4c7dc0d52cc54