The main differences is the split of cm_surface functionality with
cm_surface and cm_feedback_surface.

There can only be one cm_surface to set, unset image descriptions. When
cm_surface is destroyed, the image description is automatically unset.

There can be multiple feedback_surfaces for one surface though.
Now the "preferred_changed" signal can be an initial event.

Creator params now have a new request: set_luminances.

Signed-off-by: Joan Torres <joan.torres@suse.com>