Default network layout: add or increase "straight line" preferences

[mvences]

This issue is about the default that the program uses when creating a network. It is difficult to explain, I can better demonstrate it. Again, this might be a super easy or very complex issue to fix. Basically, the program should be fine tuned so that it favors drawing nodes in a straight line, even if there are bifurcations. I will demonstrate what I mean once we talk about all these issues.

[StefanPatman]

This would require writing a new layout algorithm, left for later in development. For now, it is possible to put nodes in a straight line by manually dragging them with node snapping on.