Unstable state; need to merge from master

djangoapps/courseware/modules/vertical_module.py

@@ -5,6 +5,9 @@ from mitxmako.shortcuts import render_to_response, render_to_string
 from x_module import XModule
 from lxml import etree
 
+class ModuleDescriptor(XModuleDescriptor):
+    pass
+
 class Module(XModule):
     id_attribute = 'id'