title: Conflict using both memory_profiler and docopt
body: <p>I have a Python program that uses docopt and appears to parse command-line arguments just fine.  However, when I attempt to include memory_profiler in the invocation (with -m memory_profiler), docopt fails to parse the command and prints the usage statement.  Here is a sample program:</p>
  
  <pre><code>"""
  Usage:
    ids_transform [options]
    ids_transform --block BLOCK_MSG
    ids_transform --unblock
    ids_transform --version
  
  Examples:
      ids_transform.py --block '2013-03-15 IM#123456 database down'
      ids_transform.py -c ../shared/etc/ids_transform.yaml
  
  Options:
    -h --help                 show this help message and exit
    -c CONFIG --config=CONFIG config file
    -d --debug                begin debugging
    --force                   override block file; force run
    --profile                 use cProfile to gather statistics on process
  """
  
  from docopt import docopt
  
  
  if __name__ == '__main__':
      arguments = docopt(__doc__, version='1.0.0rc2')
      print(arguments)
  </code></pre>
  
  <p>Here is a successful invocation:</p>
  
  <pre><code>$ python ids.py -d --force -c foo.yml
  {'--block': False,
   '--config': 'foo.yml',
   '--debug': True,
   '--force': True,
   '--help': False,
   '--profile': False,
   '--unblock': False,
   '--version': False,
   'BLOCK_MSG': None}
  </code></pre>
  
  <p>And here is the error when utilizing the memory_profiler:</p>
  
  <pre><code>$ python -m memory_profiler ids.py -d --force -c foo.yml
  Usage:
    ids_transform [options]
    ids_transform --block BLOCK_MSG
    ids_transform --unblock
    ids_transform --version
  </code></pre>
  
  <p>What am I missing?</p>