Update webchurch to b71e0b6eef50bc05149c9a9e8a166c3c95f01697
Style updates for new wc editor
Fix recursion bug in phys.js listToArray
Port phys.js arrayToList to new list backing
Teach animatePhysics to use side effects
Modularize and uglify Box2d
First pass of new injector script
Add globals shim, use vega
Add mathjax, which got lost
Add box2d and plinko to chapters that need them