title: Django startswith unicode
body: <p>Is it possible to get <code>Author.objects.filter(surname__istartswith='Z')</code> return results that also start with 'Ž', 'Ź' etc.? </p>
  
  <p>The only solution that comes into my mind is to flatten <code>surname</code> with unicode transliteration and save it as <code>surname_flat</code> in db. Then <code>Author.objects.filter(surname_flat__istartswith='Z')</code> would work, but it requires database migration.</p>
  
  <p>I'm using postgres.</p>