title: First call to pytz.timezone is slow in virtualenv
body: <p>I have installed pytz (v2013.8, but it happens in 2013.b, 2011k) in a virtualenv.  The first call to </p>
  
  <pre><code>pytz.timezone("US/Eastern")
  </code></pre>
  
  <p>takes about 4 seconds.  In a regular environment this is essentially instantaneous.  </p>
  
  <p>Does anyone have a trick to get this to run faster?</p>