Be able to recover from ChucK VM hang or process overload

[terryzfeng]

When you try to do too much processing, the audio thread will overload and thus never return control back to UI. You end up with a lot of crackling and your tab essentially dies.

while (true) {};
1::second => now;

i.e The machine appears to be hanging, would you like to abort?

Would be great to have a way to restart VM so that you can recover from this state rather than being forced to reload the page.