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.