Add "view as student" mode

[touretzkyds]

As an instructor, I get a different display than what my students see. This makes it difficult for me to write instructions for my students since I don't know what the display is showing them as they submit jobs, check the queue, cancel jobs, etc.

It would be good to have a mode where instructors can pretend to be students and thus see things presented the way their students will see them. Even better would be to have a mode that allowed an instructor to act as a particular student so they can see exactly the files/projects associated with that student.