Modularize

This release is the first Chartist.js release with no production dependencies. Some tiny SVG specific DOM manipulation functions replaced svg.js that was previously replacing Snap.svg. This library is now only depending on the browser standards.

A second major feature is that Chartist is now using UMD for exporting. I didn't test the common.js modules yet and if someone would like to contribute on that, I would be very thankful.

Cheers
Gion