Initial experimental import of MathJax source into Math extension as a client-side rendering supplement to the PNG rendering.
* Pulled in MathJax 1.1 (minus the 112 megabytes of PNG "fonts")
* Pulled in some of <
https://en.wikipedia.org/wiki/User:Nageh/mathJax> bits for initialization
This doesn't currently override PNG images, but does replace the text-form if you configure it.