Flexible rendering backends

[supertxtnet]

If there was the ability to plug in different back-ends this project would be super useful for all sorts of different renderings, such as PDF's, or even GUI applications. Even if this project could support Canvas as a back-end there's already a variety of places it could render, even GioUI.

This project was an early attempt to do what I'm describing above. https://github.com/benoitkugler/oksvg