Removed _change_notify

-For inspector refresh, the inspector now detects if a property change by polling a few times per second and then does update the control if so. This process is very cheap.
-For property list refresh, a new signal (property_list_changed) was added to Object. _change_notify() is replaced by notify_property_list_changed()
-Changed all objects using the old method to the signal, or just deleted the calls to _change_notify(<property>) since they are unnecesary now.

scene/2d/multimesh_instance_2d.cpp

@@ -71,7 +71,6 @@ void MultiMeshInstance2D::set_texture(const Ref<Texture2D> &p_texture) {
 	texture = p_texture;
 	update();
 	emit_signal("texture_changed");
-	_change_notify("texture");
 }
 
 Ref<Texture2D> MultiMeshInstance2D::get_texture() const {