Legend y2 distinguished

[jbbjarnason]

When using y2 with more than one series for each y/y2 axis it can get hard to recognize what applies to what.

I am not sure what would be the best solution but somehow indicate it in the legends widget would be nice.

I can make something up but if you have an idea or something different in mind please elaborate.

Thanks

[jbbjarnason]

using scale title would be the easy and sufficient way i guess, using that in the legend widget that is