True contour plots

[archaeothommy]

Although a kind of contour plot is implemented via the KDE parameter, a separate option for true contour plots is highly desirable. While a contour around all data points of a group is easily feasable (see e.g. the vignette on how to extend ggplot2), this would result in unrealistically large ore fields when you have regions with distinct clusters Therefore, clusters within groups should be somewhat automatically identified and contours drawn around each cluster separately.