Problems sorting NaN and undefined values.

I've included a simple failing test case for NaN. However, it seems it can be more severe as my real dataset causes the call stack to overflow with "Uncaught RangeError: Maximum call stack size exceeded". I believe this only occurs when using the impressive dual-pivot quicksort i.e. arrays larger than the threshold of 32.

[This](http://mail.openjdk.java.net/pipermail/core-libs-dev/2009-November/003192.html) may be of use. I'll have a closer look when I get time.