Upgrade to D3 v4

Didn't test the drawing functionality yet.
Likely to break some things.

Base64 icon support

Merge pull request #33 from tomvantilburg/master

better base64 icons support

Ready for GM

Merge pull request #32 from tomvantilburg/master

merge from Tom

ff tussendoor

Merge pull request #31 from RubioV/master

grunt grunt

First release

Merge pull request #22 from tomvantilburg/master

merge from Tom