Added custom XML Namespace to create chartist attributes on SVG elements and included basic attributes for storing values and series, this solves the data part of #11 although there are no accessibility concerns addressed with this yet
Code refactored as first isolated step is no longer required so we can stay more DRY
Fixed bug that text attribute is getting added to pie chart labels
Added option to insert nodes as first child element instead of last and changed order of piechart segment rendering, fixes #31