title: datetime and timezone conversion with pytz - mind blowing behaviour
body: <p>I'm trying to convert timezone aware <code>datetime</code> object to UTC and then back to it's original timezone. I have a following snippet</p>
  
  <pre><code>t = datetime(
      2013, 11, 22, hour=11, minute=0,
      tzinfo=pytz.timezone('Europe/Warsaw')
  )
  </code></pre>
  
  <p>now in ipython:</p>
  
  <pre><code>In [18]: t
  Out[18]: datetime.datetime(
      2013, 11, 22, 11, 0, tzinfo=&lt;DstTzInfo 'Europe/Warsaw' WMT+1:24:00 STD&gt;
  )
  </code></pre>
  
  <p>and now let's try to do conversion to UTC and back. I would expect to have the same representation as:</p>
  
  <pre><code>In [19]: t.astimezone(pytz.utc).astimezone(pytz.timezone('Europe/Warsaw'))
  Out[19]: datetime.datetime(
      2013, 11, 22, 10, 36, tzinfo=&lt;DstTzInfo 'Europe/Warsaw' CET+1:00:00 STD&gt;
  )
  </code></pre>
  
  <p>Yet we see that <code>Out[18]</code> and <code>Out[19]</code> differ. What's going on?</p>