Modify create_classifier to return shared_ptr
Modify create_storage to return shared_ptr
Clarify classifier_base has ownership of storage_base
Modify create_regression to return shared_ptr
Clarify regression_base has ownership of storage_base
Modify create_anomaly to return shared_ptr
Modify create_graph to return shared_ptr
Modify create_recommender to return shared_ptr
Modify create_norm to return shared_ptr