title: Django Haystack-Xapian search fails with special characters and spaces
body: <p>I'm working on an existing Django project which uses haystack with xapian backend for a global search feature. However the search seems to fail while I search with some special characters like &amp; and spaces etc. I tried but could not find out a way to fix it. </p>
  
  <p>Is there a way I can escape these characters and make the search work? I'm using PostgreSQL at the back-end. Any pointers will be very helpful.</p>
  
  <p><strong>Update:</strong> Search feature uses a SearchForm and the query string comes in q field of the from. This is used as below in the code.</p>
  
  <pre><code>sqs = self.searchqueryset.auto_query(self.cleaned_data['q'])
  </code></pre>
  
  <p>I've tried using:</p>
  
  <pre><code>sqs = self.searchqueryset.filter(self.cleaned_data['q'])
  </code></pre>
  
  <p>and</p>
  
  <pre><code>sqs = self.searchqueryset.filter(content=Clean(self.cleaned_data['q']))
  </code></pre>
  
  <p>with no luck. I'm still not able to search with spaces and special characters like &amp;.</p>