MathJax doesn't complete initialization in IE9 when in IE9 Standards mode

[shogun70]

1. Using IE9 Platform Preview 5, visit http://mathjax.org/demos/tex-samples/
2. The TeX equations remain unprocessed
3. Use IE Developer tools to switch the page to IE9 mode - the equations are still unprocessed.

IE notifies of an error at around line 1815 in MathJax.js
Specifically, there is a comparison (RegExp.$2 !== "") which seems always valid on other browsers, but not in IE9.

[shogun70]

I have a fix ready for review.
Try it out at http://s3.amazonaws.com/dist-meekostuff-net/MathJax/default/test/sample.html

[shogun70]

This fix merely changes the check to
(RegExp.$2)
which should always be valid.
However, I don't think we should be writing our own URL parser if there is already good code available. I recommend we use Steven Levithan's parseUri:
http://blog.stevenlevithan.com/archives/parseuri
It's small and has a MIT license. There's a test-page as well.

[dpvc]

The change looks good. You can go ahead and commit the change.

[dpvc]

I have committed the change, so am closing this issue.