Resolve problem of pairing the (fake) links in human state provider

[kouroshD]

Trying to make pairs between the fake links introduced here , we noticed that it it can't make correctly the pairs, for all links. Investigating more, on the code of the human state provider in function static void createEndEffectorsPairs we understood that it guarantees that it will find a pair, but it could not guarantee the minimum distance neighborhood (at least) in the case of adding the fake links. Therefore, we modified the code , such that now it can find minimum distance link pairs (but still I can not guarantee that it always find the minimum distance pair of the links). In any case, I suggest later, we can merge this commit, as it have better performance and more predictable output.

[yeshasvitirupachuri]

Also, we need to update the function name from createEndEffectorsPairs to something like createLinkPairs

[kouroshD]

Since we have found and resolved the problem as mentioned in the first comment, I close this issue.