[v2] replacement for ModestImage dependancy

[ambarb]

ModestImage was implemented as a dependency to better control matplotlib output. Unsure how much affects _common but this certainly affects _futurepyCHX

• ModestImage is not part of standard analysis environment
• Understand now that ModestImage is/was a young projects with single developer
• Is ModestImage still being supported? Python 3.3 was the last PyPI release. https://pypi.org/project/ModestImage/

It seems functions imported from modest_image are:

• from modest_image import imshow
• from modest_image import ModestImage, imshow

In the following modules:

• chx_compress_analysis.py
• chx_generic_functions.py
• chx_libs.py
• Two_Time_Correlation_Function.py

It seems only that imshow is used.

• [x] I see no function calls that start with ModestImage in code base
• [ ] what about in analysis pipeline? ModestImage is only imported in Two_Time_Correlation_Function; so check .ipynb for papermill.

So basically, it seems we need to understand how imshow from ModestImage improved plotting of 2D images.

[danielballan]

@tacaswell Can you remind me what the motivation was for this and how we might get a similar result from plain mpl?