Ngaro JS performance improvements

The Ngaro in JavaScript (jsvm) is now fast enough to actually be useable. It's still slower than the Java and C implementations, but I'm now comfortable with the performance.

Now to apply some CSS to improve the look and feel a bit....

For those who are curious about what I did, all it took was:

• Put in a loop to call vm_process() more than once per 10ms interval

I also experimented a bit with loop unrolling, but didn't notice enough of a payoff for the code duplication it brought.