Force update the cursor renderer after theme or size changes; otherwise
we'll be stuck with the old theme and/or size until something else
triggers resetting of the cursor.
Split up the X11 backend into two parts, one for running as a
Compositing Manager, and one for running as a nested Wayland
compositor.
This commit also cleans up the compositor configuration calculation,
attempting to make it more approachable.
https://bugzilla.gnome.org/show_bug.cgi?id=777800
The method used for getting the current logical monitor (the monitor
where the pointer cursor is currently at) depends on the backend type,
so move that logic to the corresponding backends.
https://bugzilla.gnome.org/show_bug.cgi?id=777732
Introduce two new clutter backends: MetaClutterBackendX11 and
MetaClutterBackendNative. They are so far only wrap ClutterBackendX11
and ClutterBackendEglNative respectively, but the aim is to move things
from the original clutter backends when needed.
https://bugzilla.gnome.org/show_bug.cgi?id=768976
