Filter Bug

[CMG]

Changing the dropdown on the filter doesn't always change the frequency graphic unless its LPF or HPF, all the others seem to offer no update.

Also adding modulation to the FREQ seems to visually work, but offer no audio modulation.

[Christoph Hart]

Yeah, the other filters aren't biquads and don't have IIR coefficients that can be plotted, but I'll add some dummy coefficients to hide this :)

But the Frequency modulation is supposed to work. I'll investigate.