Just like the ClutterBindConstraint, the ClutterAlignConstraint should
listen to "queue-relayout" of its source actor, not
"notify::allocation". That's because the latter will queue a relayout
during an allocation cycle and might cause relayout loops.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1296
We're going to remove the "allocation-changed" signal from ClutterActor
since it's no longer needed now that ClutterAllocationFlags are gone.
So listen to "notify-allocation" instead, which has been the recommended
thing to do for some time now anyway.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1245
In cogl use cogl-config.h and in clutter use clutter-build-config.h. We
can't use clutter-config.h in clutter because its already used and
installed.
https://bugzilla.gnome.org/show_bug.cgi?id=768976
