Migrate build system

[windytan]

Possibility to migrate from autoconf to CMake should be investigated. It would simplify the discovery of external dependencies and creating test cases, and also make the build system more accessible to developers and easier to keep secure.

• [x] Create a branch replacing automake files with meson.build
• [x] macOS library discovery for Homebrew, MacPorts (esp. liquid-dsp)
• [x] Debian/Ubuntu library discovery
• [x] Linux build in CI
• [x] macOS build in CI
• [x] Windows (Cygwin) build in CI
• [x] Windows (MSYS2/MinGW) build in CI
• [ ] Ensure it works for cross-compilation
• [x] Update build instructions in README & wiki

[michal2229]

Please take a look at meson ( @https://mesonbuild.com ) - it's getting quite popular in FOSS world and I think it is pretty much justified. I used it in a few projects and I find it way easier and more readable/maintainable than CMake. Please note I might be biased here, since I'm not an build system expert and meson just clicked with me, also I heard some mentions about 'modern' CMake, which might be on par with meson now.

[windytan]

Thanks! I'll check out the alternatives, too. Meson is a new one for me. The biggest plus side of good old CMake would be it's so widely used in C++ projects nowadays, and easily available for many platforms. + Lately my own experience with autoconf on macOS hasn't been that seamless.