2.2.0

Fixed

• Missing header files for newer GCC versions, thanks to @vamega (#32).
• Use-after-free of blackhole working directory path.
• A few compiler warnings on unnecessary allocation of string literals.

Added

• Deprecation warnings if rules are specified in YAML format.
• Unlink socket file before bind if SO_REUSEADDR is used.
• Support for Linux abstract sockets.
• Support for matching an existing Unix domain socket or abstract socket.
• stream/datagram aliases for tcp/udp socket types.
• Flag to prevent unlinking of socket files when closing sockets.

Changed

• Rule files (-f) are now just a list of newline-separated rule (-r)
  arguments instead of YAML files.
• Improve and overhaul README and man page.
• Split build instructions into separate file.
• Include URL to README in usage if manpage is not being built.
• Turn into a Nix Flake.
• Improve serializer to be more robust in end-of-stream conditions.
• Bump requirements to require at least GCC version 9.

Removed

• Badges (eg. LGTM and build status) in README and Hydra.
• No longer prefer C library path over RTLD_NEXT.