This class largely implements the sliding views found in the Path 2.0 and Facebook apps.
The ViewDeckController supports sideview in all directions (left, right, top, bottom), in any combination: you can leave any of them nil for example. You can pan the center view to the side to reveal any side view.
Provides a delegate to control panning, opening and closing side views.
There's also a bunch of messages defined to open or close each side appropriately.
Integrates nicely with UINavigationController. Handles rotation and resizing.