JUCE effect plugins now work (kind of) and parameters are reflected too

[atsushieno]

It's been one of the major issues that JUCE effect plugins, not synth, crashed at processing audio inputs. It was partly due to some JUCE issues (e.g. 837) but other issues were in our own code. The issue is now fixed and we can use JUCE effect plugins, for example:

• ffAudio/Frequalizer
• witte/Eq
• jatinchowdhury18/ChowPhaser/
• szkkng/SimpleReverb

/

I also noticed that the plugin parameters were not reflected to the actual audio processing (due to lack of change notifications to listeners), which should be also fixed now. This change also affects synth plugins.