Fixed the use of the zoom feature when you use the base tag html.

Fixed the use of the zoom feature when you use the <base tag html. TODO: compile also the c3.min.js.

Related issues, please read:
https://github.com/mbostock/d3/issues/1510
http://stackoverflow.com/questions/18259032/using-base-tag-on-a-page-that-contains-svg-marker-elements-fails-to-render-marke/18265336#18265336