Some UI suggestions for the new sorting interface for categories and courses.

1. Add a select all checkbox for categories and get rid of the first sorting drop down + make the heading "Sort selected categories"
2. Combine the second 2 sorting drop downs and get rid of the "Do not sort" options (change the sort categories string to sort sub categories).
3. Add a confirm before sorting (because this is a global change - not just a change for the current view)