secp256k1-sys 0.8.1

FFI for Pieter Wuille's `libsecp256k1` library.
Documentation
# 0.8.1 - 2023-13-16

* [Implement `insecure-erase`]https://github.com/rust-bitcoin/rust-secp256k1/pull/582.

# 0.8.0 - 2202-12-19

* Update libsecp25k1 to v0.2.0

# 0.7.0 - 2022-12-01

* [Make comparison functions stable across library versions]https://github.com/rust-bitcoin/rust-secp256k1/pull/518
* Add public methods `cmp_fast_unstable` and `eq_fast_unstable` for types that contain an inner array (see PR linked above).

# 0.6.0 - 2022-06-21

* [Bump MSRV to 1.41]https://github.com/rust-bitcoin/rust-secp256k1/pull/331
* [Re-implement `Ord` on `PublicKey` using upstream ordering function]https://github.com/rust-bitcoin/rust-secp256k1/pull/449

# 0.5.1 - 2022-04-30

* [Fix WASM build]https://github.com/rust-bitcoin/rust-secp256k1/pull/421

# 0.3.0 - 2020-08-27

* **Update MSRV to 1.29.0**

# 0.2.0 - 2020-08-26

* Update upstream to `670cdd3f8be25f81472b2d16dcd228b0d24a5c45`
* [Add missing return]https://github.com/rust-bitcoin/rust-secp256k1/pull/195 `c_int` to `NonceFn`
* [Got wasm support working again]https://github.com/rust-bitcoin/rust-secp256k1/pull/208
* Removed `cc` restriction, rustc 1.22 support [now requires some downstream effort]https://github.com/rust-bitcoin/rust-secp256k1/pull/204
* [Exposed a reference to the underlying byte array]https://github.com/rust-bitcoin/rust-secp256k1/pull/219 for all byte-array-wrapping types
* Allow all-zeroes `Message` [to be constructed]https://github.com/rust-bitcoin/rust-secp256k1/pull/207
* Expose `secp256k1_ec_pubkey_negate` [from upstream]https://github.com/rust-bitcoin/rust-secp256k1/pull/222