title: pass list of strings to fabric task
body: <p>I'd like to pass a list of strings to a fabric task as an argument.  For instance, for the following fabfile:</p>
  
  <pre><code>def test(names):
    print names
  </code></pre>
  
  <p>I would like to pass "fab test:[tom, dick, harry]" and have the list print out.</p>
  
  <p>Is this possible to do in fabric by default, or do I need to pass a string and split it myself?</p>
  
  <p>Thanks!</p>