Currently, `./setup.py --help-commands` displays extra commands in a random (dict iteration, probably?) order, as can be seen with the following minimal example:

    from distutils.command.build_py import build_py
    from distutils.core import setup

    class foo(build_py): pass
    class bar(build_py): pass

    setup(cmdclass={"foo": foo, "bar": bar})

(`./setup.py --help-commands` will sometimes display `foo` before `bar`, sometimes `bar` before `foo`.)

For consistency, and especially because setuptools adds a lot of extra commands, it would be nice if the help listing these extra commands was sorted instead.