added decorator for inheriting docstrings for subclass methods, updated get_referrers() to filter most recent versions of objects by default
added decorator for inheriting docstrings for subclass methods, updated get_referrers() to filter most recent versions of objects by default

kbase/data_api,kbase/data_api,kkellerlbl/data_api,mlhenderson/data_api,kbase/data_api,kbase/data_api,mlhenderson/data_api,kkellerlbl/data_api,mlhenderson/data_api,mlhenderson/data_api,kkellerlbl/data_api,kkellerlbl/data_api,kbase/data_api,mlhenderson/data_api,kkellerlbl/data_api