Mirror standard output plot class

[braden6521]

• Added a StandardPlotOuptut class to the CSP directory. This produces standard formatted plots.
• Added example and unit tests for StandardPlotOutput.
• Added processing steps to curvature plots when viewing orthorectified images of a mirror. This helps make otherwise unviewablely noisy images understandable.

[braden6521]

@e10harvey. Thanks for your review. I've made the following updates, could you please re-review?

• I updated the docstrings to be hashtags for private members.
• On that note, I also added more documentation to the StandardPlotOutput class itself (there were a few places where I thought it was lacking).
• I also added some more checks to the unit test.
• I'm not sure how to add randomness into the unit test. Since we are comparing generated images to saved images, the inputs have to be the same every time. I can see cases where this could be employed in the future though on other tests.

[braden6521]

Thanks @e10harvey!