Move Wayland support (i.e. the MetaWaylandCompositor object) made to be
part of the backend. This is due to the fact that it is needed by the
backend initialization, e.g. the Wayland EGLDisplay server support.
The backend is changed to be more involved in Wayland and clutter
initialization, so that the parts needed for clutter initialization
happens before clutter itself initialization happens, and the rest
happens after. This simplifies the setup a bit, as clutter and Wayland
init now happens as part of the backend initialization.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1218
Inhibiting remote access means any current remote access session is
terminated, and no new ones can be created, until remote access is
uninhibited. The inhibitation is ref counted, meaning there can be more
than one inhibitor.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1212
The order and way include macros were structured was chaotic, with no
real common thread between files. Try to tidy up the mess with some
common scheme, to make things look less messy.
