title: Django: Add field to model formset
body: <p>I can I add fields to a model formset? It seems you can add fields if you user normal formset but not with model formsets (at least it's not the same way). I don't think I should use inline formset either ..?</p>
  
  <p>I want to let users edit their photoalbum (django-photologue). So far I've manage to do this:</p>
  
  <pre><code>PhotoFormSet = modelformset_factory(Photo,
                                         exclude=(
                                          'effect',
                                          'caption',
                                          'title_slug',
                                          'crop_from',
                                          'is_public',
                                          'slug',
                                          'tags'
                                         ))
  
  context['gallery_form'] = PhotoFormSet(queryset=self.object.gallery.photos.all())
  </code></pre>
  
  <p>The problem is that I have  to add a <strong>checkbox</strong> for each photo saying "Delete this photo" and a <strong>radio select</strong> saying "Set this to album cover".</p>
  
  <p>Thanks in advance!</p>