Change the `MathJax.Hub.Queue(initializeRequest)` to a simpler function call (`initializeRequest.call(this)`). This was failing to give a proper context to initializeRequest, and `this.value` was turning up as `undefined`. Also add a fallback if we need to display some code before MathJax finishes its original typesetting. I was stubbing out `Queue` in my specs, so the tests had to be changed around a little.
These files really should be in the capa module, but we don't have a way to load js from there at the moment. (TODO)