Gets requirements from server

Doesn't update new game requirements table properly yet, also need to
add new requirements to the RequirementsListModel
Authors: dbeckwith, quan1992
Fixes some bugs

A few visual bugs and bugs with loading requirements. The game tree will
now also update when a game finishes.
Authors: dbeckwith, quan1992
Merge pull request #55 from dbeckwith/team9dev

updating get_requirements branch
Changes user controller to be a singleton

The controller model used in the rest of the code is to use singletons.
So instead of doing new CurrentUserController().getUser(), you do
CurrentUserController.getInstance().getUser(). This makes sense because
there should only be one instance of the controller at a time.
Also removed tests for methods that were deleted in GameModel.
Also now recognizes the user who is logged in and won't let them
estimate a requirement twice.
Merge pull request #56 from dbeckwith/feature-get_requirements

Feature get requirements