Add meson build support
This series aims to add meson build support. I've successfully managed to build and run mutter and gnome-shell using this. All but one of the commits are not directly meson port, but preparations and clean ups done while making preparations to get rid of old artifacts related to the current days mutter being three separate projects merged together.
There are still things to do to remove the barriers between them further, but I'd say is out of scope for this particular series.
An incomplete list of overall changes:
- Unconditionally build various features and components that before was conditionally included
- Remove GLES1 support
- Remove fixed pipeline support
- Remove ARBfp pipeline support
- Remove various left-over/unused things
- Remove clutter examples
- Clean up the chaotic include macro mess
- Require various dependencies that before was optional
An incomplete list of differences between meson and autotools:
- meson test will test cogl, clutter and mutter, not only cogl and clutter.
- clutter and cogl test wrappers are not generated
- when running the test suite, non-installed libraries and plugin are used
- tests are not installed yet
This is the second meson setup I ever did, so please look carefully as I'm sure there are mistakes or better ways to do various things.