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

Initialized to what? we don't know the candidates yet. Do you mean initialize a large empty list for performance? growing a long list is an amortized constant factor, right? I'm sorry, I don't have enough background in scikit learn to understand the motivations for some of your suggestions, more detail would be welcome. This is GSOC code; I am guessing the author Maheshakya would probably benefit from the detail too.