Finalize CCD characterization routines.

We have canned routines for acquiring CCD characterization data, but need to pin down the ones we like, flesh out a few others, and put them in the right order. Murdock is writing up a proper reference document, but in the immediate term we need:

• proper routines to set the ADC offset levels.
• proper routines to maximize the VDD, VRD, VDD&VRD S/N.
• the final set of canned flat acquisition sequences.
• the final Fe55 sequence.

We have prescriptions for most of these from JEG.

An important desideratum is that these should yield good enough bias, dark, and flat sequences to generate reference superbiases, etc.