title: Set initial value of checkbox dynamically
body: <p>I have a MultipleChoiceField with a CheckboxSelectMutliple widget:</p>
  
  <pre><code>weight_training_days = forms.MultipleChoiceField(
      help_text=u'(Required) 3 days must be selected',
      widget=forms.CheckboxSelectMultiple(attrs={
          'inline': True,
      }),
      choices=(
          (0, "Mon"),
          (1, "Tue"),
          (2, "Wed"),
          (3, "Thu"),
          (4, "Fri"),
          (5, "Sat"),
          (6, "Sun"),
      ),
  )
  </code></pre>
  
  <p>What I'm trying to is dynamically set 3 of the 7 checkboxes to "True". Ideally I would do this from the view.</p>
  
  <pre><code>def change_challenge_settings_page(request):
  
      c = Challenge.objects.get(user__exact = request.user,chal_status=1)
  
      layout = 'horizontal'
      form =UpdateChallengeSettingsForm(initial={'goal': c.level_goal }) 
  
      return render(request, 'portal/portal_change_challenge_settings.html', {'form': form,'layout': layout,'scorecard_page': True,})
  </code></pre>
  
  <p>I know how to do this with ChoiceFields (in the example above the "goal" is a ChoiceField) but am stuck when it comes to MultipleChoiceFields. I really appreciate any thoughts/feedback.</p>