Moved login to coursetableviewcontroller, fixed some of the navigation bugs.

The splitviewcontroller delegate is causing a lot of problems when
constantly instantiating a new detail view. The code in
ClassMapViewControllers view did appear was really useful and I suspect
we will have to use that in other places as well.
Merge branch 'master' of https://github.com/zhihaoli/QuizmTeach

Conflicts:
	QuizmTeach-master/QuizApp2/ColourWheelViewController.m