+ wheel steering and throttle controls

- added quaternion wrapper (SeleneQuaternion)
- fixed V:GetNormalHeight()
- added V:GetSurfaceRotation() : quat representing "UP", should be changed to north
- V:GetSurfaceRelativeRotation() : now works, but relative to GetSurfaceRotation
- exception reporting from callbacks is now super-verbose
- changed SeleneVector/SeleneQuaternion from "struct" to "class" to avoid similar constructor calls returning same object
- new icon