Investigate better triangulation algorithm

Currently we are using qTriangulate() and then splitting up the triangles afterwards. This is similar to what the Loop-Blinn paper does, but our triangulator seems to produce a lot of very narrow triangles. The issues are especially noticeable when using the stroke shader (which is not discussed by Loop-Blinn).

Investigate either finding a better algorithm, or creating a new one that creates suitable triangles that don't need to be split.