matplotlib pinch/pan dynamic view
I added MPLView.py as a two finger pan/zoom interface to matplotlib.
still somewhat rough around the edges, but reasonably responsive, using low rez during positioning.
this also is an example of using two simultaneous ObjC gesturerecognizers to simplify touch handling. this could have been done using conventional touch handling, but i eventually plan to add single tap cursor, and perhaps longtap property editing, etc