title: Django formset cleaned_data empty when submitted form unchanged
body: <p>I've been experiencing a weird problem, regarding Django 1.4 and formsets: when the submitted data is unchanged, the cleaned_data field of the formset is empty, even if the formset itself passes the validation.</p>
  
  <p>Here is an example:</p>
  
  <p><strong>forms.py:</strong></p>
  
  <pre><code>class NameForm(forms.Form):
      name = forms.CharField(required=False, initial='Foo')
  </code></pre>
  
  <p><strong>views.py:</strong></p>
  
  <pre><code>def welcome(request):
  
      Formset = formset_factory(NameForm, extra=1)
      if request.method == 'POST':
          formset = Formset(request.POST)
          print '1.Formset is valid?', formset.is_valid()
          print '2.Formset', formset
          print '3.Formset cleaned_data', formset.cleaned_data
      else:
          formset = Formset()
      return render_to_response('template.html', locals())
  </code></pre>
  
  <p>Although <code>formset</code> is valid, and it actually contains data, line 3 prints a list of an empty dictionary, unless I've actually changed the initial value in the field.</p>
  
  <p>This seems weird to me, but I'm probably doing something wrong. Any help?</p>