mouse-wheel dollying
mouse-drag rotating
shift-mouse-drag panning

since right-button mouse dragging isn’t yet supported by Morphic.js,
I’ve currently mapped panning to dragging while holding down the
keyboard’s shift key
fix scrolling-scaling for actual mice

for some strange reason x and y seem to be swapped on the particular
mouse I’m trying this on. Since this seems to work for ScrollFrames,
however, I’m not yet ready to change the event dispatching code in
Morphic.js