add proctor admin buttons for override and reset

* Added proctor admin buttons for staff override and student reset -
  uses the same buttons/theme as staff debug/submission history.
  These buttons are *always* visible at the top of the page for staff
  users. The override button shows the current override status and the
  student admin button displays a modal with a form to reset a given
  user.
* Combined all proctor templates into proctor.html
* Removed all proctor JS alert() calls
HACK: fix courseware import error for static assets