switch to meson build + refactor code to remove compile warning

node.c

@@ -5,6 +5,7 @@
 
 static void destroy_notify(struct wl_listener *listener, void *data)
 {
+    (void)data;
     struct diyac_node_descriptor *node_descriptor =
         wl_container_of(listener, node_descriptor, destroy);
     wl_list_remove(&node_descriptor->destroy.link);