Needs the meson branch that adds a cargo module for building library
and executable targets:

https://github.com/mesonbuild/meson/pull/2616

TODO:
* gtk-doc documentation
* symbol visibility: must use symbol prototype macros instead of
  relying on libtool symbol regex or a linker script
  - MSVC support also needs this
* introspection bindings
* vala bindings
* LC_MESSAGES localization