Access violation when instructor tries to view course

[s-edwards]

When an instructor clicks on the "description" or "grades" link for an assignment, they are taken to the view page for that assignment. The breadcrumbs at the top of the page include links to view the course (i.e., all offerings of the course), and the institution (i.e., all courses from that institution), but these links produce Internal Server Error pages because of authorization failures.

This is possibly related to (or even the same as) issue #29.