Display number of data points that make up each mean value on plot tooltips

[David Platten]

Would be useful to display the number of data points that have contributed to mean values on the plot data points. This could be displayed in the tooltip information when the user hovers of the point.

[Ed McDonagh]

Agreed - that is one of the things we had thought of in the office here whilst playing with your graphs :)

[David Platten]

Added display of number of data points that have contributed to the mean value in the tooltip on the dxfiltered column plot. Resolves #138.

→ <<cset d1374aec9903>>