Enable 7+ variable graphs

[Perry-RU]

Support for 7+ variable graphs.
Support to choose line color on graph of specified variable.

[devinaconley]

Will look at some possibilities for 7+ variable graphs. I wanted to avoid arbitrary length argument lists for safety, but that very well might end up being the best option.

Planning on overhauling the listener soon anyways -- will include configurable line color in that effort

[devinaconley]

Configurable color was added in latest release (#5). Support for 7+ variable graphs should be in soon

[phdv61]

Sorry
moved suggestion to a different topic