Merge `lineid_plot` project to S4

The ['lineid_plot`](https://github.com/phn/lineid_plot) package is great. But I always get some problemd installing it into a `conda` environment. Thus, I preferred to merge it into S4.

This can be used through the `s4.plottols.plot_line_ids()` function. 

I also created an IPython notebook that it is based on the [website](https://phn.github.io/lineid_plot/).