Initial work on new student progress for teachers

This is the initial work for the new student progress for teachers.

It includes some additional work on the table-based progress2 before restarting on a div-based progress3.

The rendering of the dots and bars is done in Javascript so that we can potentially add ajax support which will do realtime updates as a class makes progress.

Lots of work left, including heuristics for coloring, deciding on colors, making the dot not hide interesting stuff, context menus, support for longer courses, deciding what to do about those pesky single-level stages, etc.