BREAKING CHANGE: the order of these operations was inconsistent
across the different VMs. Go VM was the only one to first modulate
and then apply note tracking multiplication. But that made most
sense. So now all different VM versions work in this same way.
When voice was silent, the exponential decays in the filter unit
were causing the high pass component to eventually denormalize,
causing high CPU loads. The solution is the same as in the delay
unit: add and subtract a small number from the value, causing
essentially a flush to zero.
https://en.wikipedia.org/wiki/Subnormal_numberFixes#68.
BREAKING CHANGE: The problem with crush was that it had very few usable values. This changes the crush to map the value nonlinearly, so the crush resolution is bits. Still the upper portion of the values is not very usable (bits 12-24 i.e. hardly any crushing), but at least the lower portion is usable. But now crush resolution has slightly different meaning.
