enable parameter scaling in log plotters

[mmckerns]

Currently, plotting with mystic log_reader (and similar) autoscales, so if two parameters have vastly different scaling, then the best way to scale the parameters is often to split the parameters into multiple plots (one for each scale). It would be better to also have the option to use multiple scales within a single plot.

[ricor07]

Hello, I'd like to join the project and work on this.

[mmckerns]

Great. The easiest thing to do is build and submit a PR. Feel free to DM me (or post in the issue) if you have questions.