Finally ported the rubberband router from Ruby to Nim

[PMunch]

I see, very interesting. Still not entirely sure how it decides which side of 
the terminal to pass (thinking especially of the pink path going outside the 8 
terminal to accommodate the blue). It seems like there is some extra weight 
calculation in the routing algorithm (some of those doesn't seem shortest 
path), but I guess all this is better described in the paper.