update readme

Merge pull request embertec-eng#4 from huttli/master

fix error on loop end

Merge pull request embertec-eng#3 from huttli/master

fix typo

Merge pull request embertec-eng#2 from huttli/master

dedup before use d3.geom.voronoi

Tag our own version

update doc and build folder

update readme and build results

update README

update built file for distribution

Building nv.d3.js and nv.d3.css