Donut Buster Phase 2

Phase 2 of Donut Buster. Fixed some issues with Phase1 data collection.

1. Max datapoints increased to 50.
2. Fixed, hopefully, Hy's "2 step" issue with walk=Fixed step.
3. Persist setting of Donut Buster.

Improvements:

1. Improved "refine curve fit" to better deal with outliers.
2. Added default SEP profile for scopes with central obstructions (donuts).
3. Added option to tweak outlier removal.
4. Added "Scan for Start Position" option.
5. Focus Advisor updated to include Donut Buster and appropriate SEP Parameters.