Arcs Picking Up Future Layout Positions

[everbeek]

When I do some mapping expansions, do some undo and redo, I see that edges occasionally end up pointed at where the nodes will be in the next frame.

[everbeek]

Interestingly, after fixing #529, this changed slightly. Now, the position problem only expresses as a very quick "blip" of the node in question jumping to the incorrect position, then going back to where it should be, then following a correct course of animated movement to the correct end point.

[everbeek]

Can't find the cause. Making low priority.