[ANALYZER-2468] - Sunburst chart shows zero value columns when Dimension is in Column
* Fixes a problem where subtrees having only 0 nodes would result in wedges (or rectangles, for Sunburst) with NaN attributes.
Merge pull request #61 from dcleao/ANALYZER-2468

[ANALYZER-2468] - Sunburst chart shows zero value columns when Dimension is in Column