Parallelize all examples

[endolith]

This is "embarrassingly parallel" but how to implement it while also reusing the generated data to avoid wasting time calculating that?

[endolith]

https://joblib.readthedocs.io/en/latest/parallel.html

[endolith]

I'm using joblib in some of the examples now, so I guess this will be fixed as soon as I add it to all of them. (I should use GitHub issues to track things like this more often, even though no one else is using this repo.)