added methods for class in Core
New changes and recommit
Merge pull request #46 from rlobo3/master

Changes for Class stuff
Implemented add/remove Problem to/from Sets.

This functionality can be accessed via the Problem Set list at the
bottom of the Problem view page.
Merge pull request #47 from jwien001/master

Implemented add/remove Problem to/from Sets.
Replaced new prereq dialog with autocomplete box.

And other cleanup.
Merge pull request #48 from jwien001/master

Replaced new prereq dialog with autocomplete box.
Added a problem list to the problem set view.
Merge pull request #49 from jwien001/master

Added a problem list to the problem set view.
Created solve problem view.

Renders the problem description with proper formatting and uses a code
editor for code input. More work needs to be done here once the backend
for solving problems is more fleshed out.
Merge pull request #50 from jwien001/master

Created solve problem view.
Implemented testing problems.

Allows anyone creating/editing a problem to solve it without logging it
as progress in order to verify the solution code is correct.
Merge pull request #51 from jwien001/master

Implemented testing problems.