* Full Meson support
cpp-httplib can be now built with Meson even in compiled library mode.
The library is built with LTO, supports OpenSSL, zlib and Brotli,
and the build system also generates a pkg-config file when needed.
Compared to the CMake file this one is quite small (more than five times
smaller!), and maintaining it won't be an issue :)
* meson: automatic versioning
