Move tests_docopt.py to tests/test_docopt.py
Add "test_suite" to setup.py

... so we can run "python setup.py test" to run tests.
Use unittest.TestCase in tests/test_docopt.py
Fix failing tests
Add info about testing to README.rst
Make ellipsis less greedy

Make the ellipsis ("...") less greedy so arguments following the ellipsis can have their
values matched too. Allows a script like this to work as expected:

    __doc__ = """
    Usage: mycopy <src>... <dest>
    """
    from docopt import docopt
    options = docopt(__doc__)
    print options

Prior this patch docopt would greedily consume all arguments and assign them to <src>.