ipset-pf-support, move startup and destartup to the front of the module

func block functions, modstack call deinit function names, and detect
module change when no startup functions are needed.

pythonmod/pythonmod.c

@@ -777,7 +777,7 @@ size_t pythonmod_get_mem(struct module_env* env, int id)
  */
 static struct module_func_block pythonmod_block = {
    "python",
-   &pythonmod_init, &pythonmod_deinit, NULL, NULL, &pythonmod_operate,
+   NULL, NULL, &pythonmod_init, &pythonmod_deinit, &pythonmod_operate,
    &pythonmod_inform_super, &pythonmod_clear, &pythonmod_get_mem
 };