nb_mxsynths

mx synths as an nb voice

this is more or less port of infinitedigits’ mx.synths (thanks zack!) with the following changes:

added:

• save and load presets
• dynamic parameter menu (synth specific parameters are displayed)
• modulation via nb:modulate(val) -> pairs well with sidvagn. I surfaced the mod amt parameter, so it’s midi mappable, which means modulation can be used with scripts that don’t use nb:modulate. The main use case is to temporarily morph between different parameter settings.
• fx via fx mod
• 6 voice limit

removed:

• portamento
• polyperc (already exists as separate nb voice)
• internal fx bus