Data points missing with noverlap

[nullpainter]

Using a test data set of four points - three overlapping, and one not overlapping - only the non-overlapping point renders when using noverlap and the default clusteringOpts.

I must confess to not examining the flow too closely, however when following line in symbolgroup.coffee:

for p in [0..l-3] 

is changed to the following:

for p in [0..l]

my map renders correctly, with a single aggregate value for the overlapping points, and the non-overlapping point. That being said, I fully suspect this 'fix' may well be a hack, particularly given the reference to p+1 a bit later on.