blacklabel/grouped_categories — pull request #34 by BrianXerri (2014-08-05 17:04:24+00:00)
Title: Allows axis label formatter function to be set via the options 

I noticed that if I added an xAxis label formatter function, it wouldn't be applied for the top most xAxis labels.

`tickProto.addLabel` now works more like `tickProto.addGroupedLabels`