v0.4.0

This version adds pkg-config as an alternative default feature to the existing vcpkg build. The vcpkg build is now an optional default feature.
The optional dependency on pkg-config bumps the build requirement on the libmagic C library to version 5.39 (from 2020-06-14) or newer.
Naive linking as a fallback is no longer supported; if you want to use neither pkg-config nor vcpkg you have to override the build script, see crate README.

The following environment variables are no longer supported to configure the build, check the crate README for alternatives: MAGIC_DIR and <TARGET>_MAGIC_DIR, MAGIC_STATIC and <TARGET>_MAGIC_STATIC

The following crate features are no longer supported to select the libmagic API version: v5-04, v5-05, v5-10, v5-13, v5-20, v5-21, v5-22, v5-23, v5-25, v5-27, v5-32, v5-35, v5-38
The lowest libmagic API supported by this crate is now v5.38.
If you have previously relied on the crate's default features, the libmagic API version of v5.38 remains unchanged.

The minimum supported Rust version (MSRV) is now 1.64

Added

• [breaking] Use pkg-config to link, requiring libmagic v5.39+
• Set include metadata from pkg-config and vcpkg build

Fixed

• [breaking] Fix C type of buffer param in magic_buffer
• Only include required files in .crate

Other

• Bump MSRV to 1.64
• Replace libc crate dependency with core::ffi
• Update pinned revision for cargo-vcpkg
• Fix crate license SPDX expression