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

> When np.empty is used, it causes an error in random projection in the next
> line. fit method in GaussianRandomProjection uses check_array from
> utils.validation and it does not allow to contain 'NaN's in the array.
> This is the error:
> ValueError: Input contains NaN, infinity or a value too large for dtype
> ('float64').

OK. Thanks for checking. Don't loose any more time on this suggestion.