Support for image based stepping / visualizations #161
Description
It shouldn't be terribly hard to add support for a stack of images that allows you step back and forth.
- do the JS manually
- find a library?
Somewhere we have a good recursion diagram....
http://beautyjoy.github.io/bjc-r/topic/topic.html?topic=berkeley_bjc/recur/recursion-trees-fractals.topic&course=cs10_fa15.html&novideo&noreading&noassignment