JP6 filter oscillations and latch-up

I've had serious troubles with the JP6 filter since I started working on it again about a week ago.

- it latched up whenever the cutoff CV was > 1.5V

- it had severe high-frequency oscillations

Today, I finally got it working again (with the Jove CV generation circuits). Here are the three things I fixed:

- Cutoff and Resonance Iabc has to go to two cells, not only one (or they will be too large)

- I had messed up and used a 3pF instead of a 330pF cap

- And even after fixing that, I realised that the caps were probably not in contact with the connectors. I redid the wiring there and everything started working.

Back to the real testing!