Implement internal FEE routine for LBNL wipe

[ I thought I had filed this earlier but apparently not. ]

The LBNL wipe routine is believed to ameliorate the tearing seen in INSTRM-7. We have a been using an external loop which is slow. Implement an internal routine instead. Specifically:

• Push parallels up to some newly specified voltage
• Ramp Vbb down to zero volts at a specified rate
• Dwell for 0.5 seconds
• Ramp Vbb back up to its original voltage at the same rate
• When Vbb reaches a defined threshold, drop the parallels to their original value
• Continue ramping Vbb

So command like:

~SEQ,[ramp_time_ms],[threshold],[parallel voltage]