Added the set object to response to the click events of camera, background and effect
Moved constants upward
Removed id="iview"
Renamed container to canvas
Revised mouse binding
Renamed rotationGroup to rot and modelGroup to mdl
Renamed slabNear to sn and slabFar to sf
Renamed mouseButton to wh, mouseStartX to cx, and mouseStartY to cy
Renamed dragging to dg