title: Overriding Size of Django Admin Multi-select Widget
body: <p>Newbie Django question: I'd like the Django admin to display more rows of choices in the multi-select widget. I have an extremely long list to select from and the default 4 rows just isn't convenient, especially when scrolling.</p>
  
  <p>Right now, that widget is rendered as <strong>select multiple</strong> but I'd like it to be <strong>select multiple size="12"</strong>. Ideally this should be for specific fields, but I can live with all fields rendering with the same size attribute.</p>
  
  <p>So where would be the optimal place in Django to change that? </p>