remove or fix zend_object_proxies

At the current state zend_object_proxies are pretty broken. - They'd need an explicit zend_objects_store_dtor otherwise zend_objects_destroy_object causes a SEGV. - Any op other than set/get or cast to bool/int/double on the object cause a fatal error because no class_entry can be retrieved, or a SEGV because calling object handlers without prior checking for existence. Mike