Script API methods must return Ref<T> instead of Reference*

ptrcall assumes methods that return a Reference type do so with Ref<T>. Returning Reference* from a method exposed to the scripting API completely breaks ptrcalls to this method (it can be quite hard to debug!).

editor/editor_plugin.cpp

@@ -220,7 +220,7 @@ EditorSelection *EditorInterface::get_selection() {
 	return EditorNode::get_singleton()->get_editor_selection();
 }
 
-EditorSettings *EditorInterface::get_editor_settings() {
+Ref<EditorSettings> EditorInterface::get_editor_settings() {
 	return EditorSettings::get_singleton();
 }