Add easy option to use Jülich coporate design color scheme in figures

[janssenhenning]

At the moment to use the colors from the Jülich corporate design in plots one must look up the hex values and use them manually
It would be nice to have something like use_jülich_colors=True to use colors cycling through the corporate colors

Additionally I painfully made the experience what kinds of issues it can cause when fonts are not completely embedded in pdf files produced by matplotlib this can be solved by setting mpl.rcParams['pdf.fonttype'] = 42. I don't know whether this should be the default, since it would make plots larger due to embedded fonts