[MRG] Locality Sensitive Hashing for approximate nearest neighbor search(GSoC)

I think I would find the alternative you propose quite confusing. I think most people would want to use this algorithm with n_candidates increasing somewhat more slowly than n_samples (the theoretical bounds I know suggest O(sqrt(n_samples)) candidates suffice). An example that uses a regime bound to work badly (fixed n_candidates) might lead people astray.