Dragging all works
Introduced new class Draggable and made imageInfo inherit from it using new inheritance schema
More progress on draggable encapsulation
Introduced new Handle class and got part way to separating handle functionality from Polygon class
Moved handle drawing functionality out of polygon and into handle
Eliminated redundant dragDown and draggable code in edittool
changed logic a bit for determining which draggable is clicked
use concat instead of push to do some things in fewer lines
introduced undomanager and got undo working for moving of handles only
Got undo working for creation of polygons and of images