Radial tree with "packed" nodes (flare)

This fork: Adjusted positioning and rotation to keep plot in view, and label orientation correct at any tree starting angle. Adjusted jitter for parent nodes. Re-added text labels. Added rollup of the size feature. Pulled flare data out of plot code file. Renamed files for re-use. Added node coloring for special cases (missing rollup feature, color callout for a nodes including certain naming).

Forked from nitaku's block: Radial tree with "packed" nodes (flare)

An experiment that adds some jitter (sort of) to the nodes of a [radial tree layout](/mbostock/4063550), in order to pack them more efficiently into space. Each node is moved alternatively towards to or away from the center by an amount of pixels that's equal to the radius of the node.

The data structure that's represented is the `flare` software package hierarchy.