Group all the three config files from clutter/cogl/meta into one
and also remove unnused configurations and replace duplicated ones
This also fixes Cogl usage of HAS_X11/HAS_XLIB to match the expected
build options
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3368>
A first step towards abandoning the CoglObject type system: convert
CoglFramebuffer, CoglOffscreen and CoglOnscreen into GObjects.
CoglFramebuffer is turned into an abstract GObject, while the two others
are currently final. The "winsys" and "platform" are still sprinkled
'void *' in the the non-abstract type instances however.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1496
This is a winsys-specific API that allows exporting a DMA buffer fd.
The CoglDmaBufHandle structure allows passing the ownership of the
DMA buffer to whoever is using it, so the winsys doesn't need to
manually track it.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/1086