Added SettingOverrideDecorator stub

CURA-1278

cura/SettingOverrideDecorator.py

@@ -0,0 +1,13 @@
+# Copyright (c) 2016 Ultimaker B.V.
+# Cura is released under the terms of the AGPLv3 or higher.
+from UM.Scene.SceneNodeDecorator import SceneNodeDecorator
+
+
+##  A decorator that adds a container stack to a Node. This stack should be queried for all settings regarding
+#   the linked node. The Stack in question will refer to the global stack (so that settings that are not defined by
+#   this stack still resolve.
+class SettingOverrideDecorator(SceneNodeDecorator):
+
+    def __init__(self):
+        super().__init__()
+