no consistent directionality in edges

[Max Eschenbach]

Ensure that the final weft and especially warp edges are always connected with a consistent directionality

[Max Eschenbach]

This has to be addressed! It will probably be necessary to restructure all the graphs to directional graphs and employ consistent directions from the get go. Lot's of work bu the only real way to go. Once done this should ease some other things in the later steps, too (creating meshes, dual, finding cycles).