Add d3/colorbrewer.js which brings Cynthia Brewer's color schemes.
SelectionTable: replaced "Randomize colors" with "Colorize" and a pull down menu.
The default entry is "CATMAID" which uses the old randomize colors.
Further entries are d3.scale.category10, etc., and Cynthia Brewer's colors.

For Brewer's colors arrays are short (3 to 9 or 12 entries) and are
considered circular for assigning colors.
AnalyzeArbor.arbor_stats is an Object, not an Array.