generate_diagram pep8 cleanup
fix typo in classes_recommended_attributes
fix python3 bug in test_brainwaresrcio (bug is only in the test, not in io class)
move fake_neo from test_hdf5io to generate_datasets so it can be used generally
implement tests for generate_datasets.py and fix bugs found by the tests
implement relationship data and functions inside neo core classes
switch to using class attribute tuples