The documentation for wayland-server.h says:
> Use of this header file is discouraged. Prefer including
> wayland-server-core.h instead, which does not include the server protocol
> header and as such only defines the library PI, excluding the deprecated API
> below.
Replacing wayland-server.h with wayland-server-core.h allows us to drop the
WL_HIDE_DEPRECATED declaration.
* Rename the constraint_create signal to new_constraint for
consistency
* Move the constraint_destroy signal to the constraint itself
* Use rotate_child_position instead of duplicating logic
* Fix inert constraint resource handling
* Style fixes