Add an associated const `Hash` to the `HashEngine` trait. Also add a
`finalize` method that converts the engine to the associated hash.
For now just use the existent `from_engine` stuff. We can refactor
later.
This function is deprecated, stop using it in favour of
`Hash::from_byte_array`.
Patch only touches test code, I'm guessing that is why lint warnings
were no showing up.
In preparation for removing a bunch of macros move all the modules to
`<mod>/mod.rs`.
Do so by running the following shell:
```bash
for mod in hash160 ripemd160 sha1 sha256 sha256d sha256t \
sha384 sha512 sha512_256 siphash24 hkdf hmac; do
mkdir $mod
mv "$mod.rs" "$mod/mod.rs"
done
```
Internal change only.
Tobin C. Harding
Jamil Lambert, PhD