A new function, wl_resource_create(), lets the compositor create a
wl_resource for a given version of the interface.  Passing 0 for the
object ID will allocate a new ID. The implementation, user data and
destructor can be set with wl_resource_set_implementation().

These two functions deprecates wl_client_add/new_object and the
main difference and motivation is the ability to provide a version number
for the resource.  This lets the compositor track which version of the
interface a client has created and we'll use that to verify incoming requests.

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>