This allows to support both orientations for the iPhone.
We now use a RootViewController for this, instead of relying only on the PhoneMainView. The root view controller is in charge of swapping the portrait-only and the landscape PhoneMainView when needed.
It also inherits the view stack management, since we now have 2 phone main views.
This is a bit convoluted, but necessary to handle the ChatRoom and the InCall views for the iPhone