Shade time series data based on QC

[AdamTheisen]

Some work was started in this area, but I don't think it was finished. Thhis is to document that we need to finish it.

[kenkehoe]

Can you give some more information on what a shaded time series will look like?

[AdamTheisen]

@kenkehoe This is just to color the data points on a time-series line plot with yellow/red depending on their QC variable if available.

[kenkehoe]

OK. We have this under the keyword assessment_overplot but I think it does need some work.

[kenkehoe]

I need to get back to this. The code is currently commented out. I'll try to find some time to get back to this. You can assign this to me.

[kenkehoe]

This has been resolved with PR #244