More guide test updates

[jeanconn]

More guide test updates including docstring updates and a new synthetic common column test.

Closes #203

[taldcroft]

Rebased after #221.

[taldcroft]

@jeanconn - added 7f28dce. This might fall into the category of functional validation and need more investigation. I'm not sure I understand the results there which are almost independent of the delta mag, and I definitely don't think a 15th mag star (mag0=8 and dmag=7) should ever spoil anything. That corresponds to 70 e-/sec.

[jeanconn]

I didn't think the 15th mag star about which you speak would be in the proseco AGASC unless it had large mag error (which is used in check_mag_spoilers).

[taldcroft]

Proseco AGASC has every star in the AGASC that is near a candidate guide or acq star with ASPQ1 > 0. Here is the MAG_ACA distribution.

[jeanconn]

Ah. OK. So probably should have had some useful demonstrable grid of spoiler tests before transitioning to the proseco AGASC, as functionally that means the available spoilers changed during development. But overall the population of concern is still small. I think this still falls more into parameter optimization, enhancement, and review as part of #220 . At worst the current code excludes candidates that are not really spoiled "enough".