Please note that this is a squshed commit and the work of:
Symbolist, macdiesel, nedbat, doctoryes, muzaffaryousaf and muhammad-ammar

Also, I replaced a number of tearDown methods with addCleanup instead.
And also remove some unneeded patch.stopall() calls.

indentation of opening bracket's line

* makes testing easier -- don't need course objects

Now looks for a status_message.json file, looks for 'global' and ${course.id} keys. Return any global message and any course-specific message, joined by <br>.

fab files need to be updated to use this new format (new filename, possibly also help manage per-course messages, or at least test for valid json)

- still needs style
- will cache for 10 seconds