Add wl_resource_create() and a version field to wl_resource
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>