Some final tweaks

Contributes to CURA-5595

cura/API/Interface/__init__.py

@@ -0,0 +1,24 @@
+# Copyright (c) 2018 Ultimaker B.V.
+# Cura is released under the terms of the LGPLv3 or higher.
+
+from UM.PluginRegistry import PluginRegistry
+from cura.API.Interface.Settings import Settings
+
+##  The Interface class serves as a common root for the specific API
+#   methods for each interface element.
+#
+#   Usage:
+#       ``from cura.API import CuraAPI
+#       api = CuraAPI()
+#       api.interface.settings.addContextMenuItem()
+#       api.interface.viewport.addOverlay() # Not implemented, just a hypothetical
+#       api.interface.toolbar.getToolButtonCount() # Not implemented, just a hypothetical
+#       # etc.``
+
+class Interface:
+
+    # For now we use the same API version to be consistent.
+    VERSION = PluginRegistry.APIVersion
+
+    # API methods specific to the settings portion of the UI
+    settings = Settings()