added hints to options; made arbitrary number of clusters for k-nearest-neighbor possible
added hints to options; made arbitrary number of clusters for k-nearest-neighbor possible

saisai/algorithms_by_other,saisai/algorithms_by_other,saisai/algorithms_by_other,saisai/algorithms_by_other,saisai/algorithms_by_other,saisai/algorithms_by_other,saisai/algorithms_by_other