Per-machine oversampling

[dlbeswick]

New versions of Buzz have this feature, it's pretty cool. You right-click on the machine and you can choose 2x or 4x oversampling (from memory.) 8x would even be useful at times.

As an example, I've implemented this function (just via a simple parameter) for my distortion effect here: https://github.com/dlbeswick/bt-edb-distort/blob/20478451b4b52853963dc49b15c1f23568b86008/src/machine.c#L248

The approach could maybe be extended to all machines in general.