CallyTexture is an accessibility object associated with ClutterTexture.
ClutterTexture is going away, so prepare by first removing the
accessibility object that would be constructed for it.
https://gitlab.gnome.org/GNOME/mutter/merge_requests/932
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