Arbor.js: asymmetry computes as well the histogram, with 10 bins.
CircuitGraphPlot: fix error with multi-skeleton nodes.
CircuitGraphPlot: new option to include the histogram of the asymmetry measurements.
Arbor.js: flowCentrality now accepts optional arguments totalOutputs and totalInputs.
Arbor.js: new function terminalCableLength
Returns sum of cable length of terminal branches and their number.
utils.js. parseArbor not only counts input and output synapses but also collects them
into objects suitable for computing the signal flow centrality.
webglapp.js: updated signal flow centrality shading.
CircuitGraphPlot: new anatomical measurements terminal cable, N terminal segments and hillock cable.

Hillock cable is the cable length of the edges of the arbor with a signal flow centrality
larger than 75%. Not using max flow centrality to be able to capture central parts
even when there are tiny branches or small amount of inputs or outputs on what is
otherwise a hillock-like segment.
Arbor.js: terminalCableLength also returns the number of branches.
Arbor.js: new function pruneBareTerminalSegments
CircuitGraphPlot: fix error in using the neuronNameService.
CircuitGraphPlot: added number of branches to anatomy.
CircuitGraphPlot: add only PC 1 and PC2 to the menus, and later add as many
PC entries as necessary to add up to over 98% of all variance.
CircuitGraphPlot: add option to prune away empty terminal branches.

Many of these branches are the product of limitations in skeleton tracing
when doing so over serial sections, and may be labeled as "not a branch".
Synapse clustering: attempt at speeding up critical parts.
Arbor.js: speed up findEndNodes by 8x
Arbor.js: speed up allSuccessors by 4x
Arbor.js: speed up findBranchAndEndNodes, and adjust other functions
to slight change of API, which accelerates other functions by
not having to create a map of branch nodes from the array of branch nodes
(which was never used directly as an array except for counting).

Returns now:
 {ends: array of end nodes,
  branches: map of branch node vs count of successors,
  n_branches: number of branching nodes}
Arbor.js: speed up partition function.

From higher than O(6n) to about O(4n).
Arbor.js: fix typo in docs