* Tweaked flycam a bit too, but not much.
* Refactored the API/C# side camera classes to avoid exposing a ton of
stuff just to do relative rotations in the arcball via quaternions.
* The arcball lookat position can also be dragged with alt-click or
middle click.
* Also supports other elements as position not just magically-selected
"POSITION" element.
baldurk