Create urls/views/templates for dev-only views

Our designers find it helpful to be able to stub out simple views that aren't ready
to be seen for production yet, and check them into version control so that other
people can see them and provide feedback. This commit introduces a few new files
and directories for this purpose, as well as a sample view that will only be seen
in dev mode, and never in production.

cms/djangoapps/contentstore/views/__init__.py

@@ -15,3 +15,7 @@ from .public import *
 from .user import *
 from .tabs import *
 from .requests import *
+try:
+    from .dev import *
+except ImportError:
+    pass

cms/djangoapps/contentstore/views/dev.py

@@ -0,0 +1,5 @@
+from mitxmako.shortcuts import render_to_response
+
+
+def dev_mode(request):
+    return render_to_response("dev/dev_mode.html")