New version is up and it's incredibly fast.

However, longest search path is disabled (for now?) because the algorithm is build differently.

It occurs to me that it might make a difference if you compared the two persons and always used the one with the least number of credits as a starting point.

In the previous version it made quite a dramatic difference. In this one I really couldn't tell if switching the persons made any difference in speed.

Many thanks, Karsten! 

I think it might be overkill to update DpLink, it doesn't have any long hops, but I will certainly study it and keep it in mind for future reference!

Cool!