Rework the Interior Camera to support larger rooms

[DarianLStephens]

While it currently does TECHNICALLY support big rooms, it's just by zooming out to fit it all.
I'd love a way to create a 'clamped camera', for use with excessively big rooms, so you can scroll your view to either side.
Think The Binding of Isaac's rooms: Small ones fill the screen and the camera doesn't move, while there are bigger ones where the camera moves to follow Isaac as he travels, but the camera won't move further than the edges of the room.