Make data plots for individual events

[mhearne-usgs]

[emthompson-usgs]

The term "regression plot" doesn't actually make a lot of sense. I think this is a legacy term and we should avoid it. We are really just plotting the data and so in general we should be calling this a "data plot" or something like that.

[wald-usgs]

Regressing a bit but...earlier these were called simply attenuation plots. The name "Distance-Attenuation Plot" would resonate the most with technical users. (We know "attenuation" is not the only physical component of amplitude decay, but that word is used for many functions)