Pie Chart - Seperate pie labels from pie element in svg

Currently the labels for pie elements are in the same SVG element as the pie elements.

I have adapted my code to jsfiddle to show the problem:
https://jsfiddle.net/gothmogg/fo5xe1nt/69/

This leeds to an overlap for small pie elements and as there is no z-index in svg.

The label of data40098 is overlapped by the pie of data777 and the label of data777 is overlapped by the pie of data66.

The best solution would be to have an extra svg element after the pie, containing all pie labels. Maybe use the "c3-chart-texts" also for the pie-labels?