Plotting pareto front in 2D control parameter plot

[SRFU-NN]

Would it be helpful to plot the control parameters that give points on the Pareto front in the 2D plots of plot_objectives?

It seems like it would make it way easier to conceptualise where the Pareto front is in control parameter space.

Example (gold map, plus the distance from [4,10]), big red points are the Pareto front:

[SRFU-NN]

We probably should add some colouring to the points, but I think the example is illustrative for now.

[SRFU-NN]

Oh, and I named the axes wrong :-D They should be N-S and E-W

[SRFU-NN]

Note that this won't be as clear in higher dimensions, since the colours "under" the Pareto front points won't correspond to the objective function values on the Pareto front. the Pareto front points will, in general, have different values than the slice plotted for some of the other control parameters.