* [Remove `Deref` impls for all hashes](https://github.com/rust-bitcoin/rust-bitcoin/pull/1450)
* [Add `AsRef` impls for all hashes from fixed-size arrays](https://github.com/rust-bitcoin/rust-bitcoin/pull/1593)
* [Add the `sha512_256` hash](https://github.com/rust-bitcoin/rust-bitcoin/pull/1413)
* [Remove the `ToHex` trait in favor of `DisplayHex` and `fmt::Display`](https://github.com/rust-bitcoin/rust-bitcoin/pull/1531)
* [Remove the now-unused `HexWriter` object](https://github.com/rust-bitcoin/rust-bitcoin/pull/1572)
* [nostd: `alloc` feature no longer enables `core2`](https://github.com/rust-bitcoin/rust-bitcoin/pull/1612)
* [Rewrite `hash_newtype` macro with new syntax](https://github.com/rust-bitcoin/rust-bitcoin/pull/1659)
* [Rename `Hash::Inner` to `Hash::Bytes`, 'Hash::*_inner` and several related conversion methods](https://github.com/rust-bitcoin/rust-bitcoin/pull/1577)
* Replace `fuzztarget` feature with [use of `cfg(fuzzing)`](https://github.com/rust-bitcoin/bitcoin_hashes/pull/111/)
* Use [`core` rather than `std`](https://github.com/rust-bitcoin/bitcoin_hashes/pull/118/) and [fix `no_std` compilation](https://github.com/rust-bitcoin/bitcoin_hashes/pull/122/)
Note that we have stopped re-exporting the `core` crate when compiling without `std`. This is technically a breaking change but it is hard to imagine what user might be affected.
# 0.9.4 - 2020-10-23
* Add `Hmac::from_inner_engines`
# 0.9.3 - 2020-10-19
* More serde macro fixes
# 0.9.2 - 2020-10-18
* Fix rustc 1.29.0 downstream issues with serde macros
# 0.9.2 - 2020-10-16
* Fix visibility issue with serde macros
# 0.9.1 - 2020-10-07
* Add `FromStr` impl to `sha256t::Hash`
* Fix `Hash::engine()` implementation for hash newtypes
* Add `sha256t_hash_newtype!` macro for creating tagged hashes
# 0.9.0 - 2020-08-27
* **Update MSRV to 1.29.0**
# 0.8.0 - 2020-08-26
* Add `as_inner` method to `Hash` trait
* Add `n_bytes_hashed` to `HashEngine` trait
# 0.7.6 - 2020-04-05
* Support hash newtypes with reversed hex serialization.
# 0.7.5 - 2020-04-02
* Add `sha256t` module for SHA-256-based tagged hashes.
* Add `FromStr` for hash newtypes.
* Add `from_hash` for hash newtypes.
# 0.7.3 - 2019-12-18
* Add `as_hash(&self) -> <inner>` method to hash newtypes.
# 0.7.2 - 2019-11-29
* Make the inner variable of `sha256::Midstat` public
* Drop the `byteorder` dependency in favor of manual endianness implementations
(later this will be in stdlib so we can drop even that)
* Fix the `hash_newtype` macro, which did not compile before
# 0.7.1 - 2019-08-14
* Add hash_newtype macro that allows third parties to create newtype structs.
# 0.7.0 - 2019-07-19
* Add `hex::Error` type for errors generated by the `hex` module.
# 0.6.0 - 2019-07-10
* Add `no_std` support, rearrange traits to not depend on `io::Write`
# 0.5.0 - 2019-06-28
* Fix panic when parsing hashes that contain multibyte characters
* Add `FromStr` to all hashes which hex-parses them
# 0.4.0 - 2019-06-23
* [Add `from_inner` method](https://github.com/rust-bitcoin/bitcoin_hashes/pull/20) to all hashes
* [Update `FromHex` trait](https://github.com/rust-bitcoin/bitcoin_hashes/pull/40) to require `from_byte_iter` method rather than `from_hex` be implemented
* Make `Hmac` midstate [an actual HMAC midstate](https://github.com/rust-bitcoin/bitcoin_hashes/pull/43)
* Require [using a constructor for `HexIterator`](https://github.com/rust-bitcoin/bitcoin_hashes/pull/44) and then [clean up the internals](https://github.com/rust-bitcoin/bitcoin_hashes/pull/47)
* [Strongly type `sha256::Midstate`](https://github.com/rust-bitcoin/bitcoin_hashes/pull/39) to allow independent serialization