Oops, don't visualize touch target as grey circle!

[#52489137]

That was just supposed to be for debugging, not committing.
Only use ExceptionHandler in production
Fix min-width to allow portrait mode on iPads

[#50691481]
only clip the visible part of a point

(Frankly, I don't think we should clip that either)
PointerEventsSupport mixin with IE fallback

[#52497845]

Zeus proliferated several copy/pasted versions of the original, ad hoc implementation found in overlayAnnotationsHolder. This mixin will help DRY up the implementation, make its intention as a pointer-events polyfill clear, and also make sure that every view that intends to have 'pointer-events: none'-like behavior applies it consistently to both mouse and touch events (which was not happening before, causing poor behavior with overlay annotations on touch browsers.)
Refactor graphView to use PointerEventsSupport

Note this does not yet apply to the event capturing and refiring in the topAnnotationsHolder. I'm not sure what is going on with that code.

[#52497845]
Also use PointerEventsSupport in PointSetView

This not only DRYs up code but removes code that added event handlers to each point in a pointset!