[GSoC17] Rewrite library with three.js

[nemesifier]

• [x] build a (mostly) backward compatible version with three.js
• [x] draw a demo graph using canvas or WebGL
• [x] update docs with new examples
• [x] add tests

[nemesifier]

@geekplux how are we doing with this issue?

[geekplux]

@nemesisdesign now should add more tests and update docs

[nemesifier]

what's the status of this issue?

[geekplux]

docs updated but examples