Custom setup() function, inserting our custom classes.

def setup(**kwargs):
    """Custom setup() function, inserting our custom classes."""

    cmdclass = kwargs.setdefault('cmdclass', {})
    cmdclass['easy_install'] = easy_install
    cmdclass['install'] = install
    cmdclass['register'] = register
    cmdclass['upload'] = upload
    cmdclass['upload_docs'] = upload_docs
    return setuptools.setup(**kwargs)