Add cluster.split methods
Add cluster.split methods

SchlossLab/Westcott_OptiClust_mSphere_2017,SchlossLab/Westcott_OptiClust_mSphere_2017,SchlossLab/Westcott_OptiClust_PeerJ_2016,SchlossLab/Westcott_OptiClust_PeerJ_2016,SchlossLab/Westcott_OptiClust_mSphere_2017