Wire in VCA decay CV.

- only downsample a source wave generated at higher sample rates
- switch to Pade approximation of sin
- new panel SVG from Befaco
- fix LED logic

Moved all chowdsp library code into specific header.
Updated .json

Made final row behaviour configurable in the menu (as is the case in the hardware).

* some code cleanup
* Percall strength should be calculated every sample

* only up/downsample if needed

* use simd for polyphonic logic
* only process CV / lights every N samples