title: Django_autocomplete_light dropdown not appearing
body: <p>I'm trying to implement django_autocomplete_light into one of my modelform's ModelMultipleChoiceFields. I've followed the tutorial and docs exactly but when I enter the first few letters into the field, a dropdown does not appear.</p>
  
  <p>models.py:</p>
  
  <pre><code>class GameForm(forms.Form):
      Players = forms.ModelMultipleChoiceField(queryset=User.objects.all(),widget=autocomplete_light.MultipleChoiceWidget('UserAutocomplete'))
  </code></pre>
  
  <p>autocomplete_light_registry.py:</p>
  
  <pre><code>class UserAutocomplete(autocomplete_light.AutocompleteModelBase):
      search_fields=['username' ]
      model = User
      choices = User.objects.all()
  
  autocomplete_light.register(UserAutocomplete,
      search_fields=['username'],
      attrs={
          'placeholder': 'Who?',
          'data-autocomplete-minimum-characters': 1,
      },
      widget_attrs={
          'data-widget-maximum-values': 4,
          'class': 'modern-style',
      },
  )
  </code></pre>
  
  <p>Visiting localhost/autocomplete/UserAutocomplete/ returns all Users in a single line with no spaces:</p>
  
  <pre><code>user1user2user3
  </code></pre>
  
  <p>I have already done the steps stated in the installation instructions which are </p>
  
  <ul>
  <li>Install the django-autocomplete-light>=2.0.0pre package with pip</li>
  <li>Append 'autocomplete_light' to settings.INSTALLED_APPS before django.contrib.admin</li>
  <li>Include autocomplete_light.urls</li>
  <li>Include autocomplete_light/static.html after loading jquery.js (>=1.7)</li>
  </ul>