Knob: add volumeRatio property to allow showing knobs with ratios other ...

...than 100 in dBV

Waveshaper, Dynamics processor: make input/output knobs respect the show in dBV setting

BassBooster: updated background artwork

Fix loading of model values on all native effect plugins: switch to using the loadSettings/saveSettings methods on the models themselves, because the old way doesn't preserve controller connections. This should work in a backwards-compatible way with the old way, I tested it.