WIP: student verification status

* Decide what to display next to courses on the dashboard, based on the course mode and verification status.
* For now, just dumps a debug message to the dashboard.  We still need to add the actual styles and messaging.

@stephensanchez @rlucioni thoughts?
Just wondering, is the `__` used here because the value it represents isn't needed, or does it have some other significance I'm not aware of?