title: Saving custom data from inline forms (django admin)
body: <p>I am using <code>django-nested-inline</code> package with two levels.</p>
  
  <pre><code>class OrdersAdmin(NestedModelAdmin):
      inlines = [PointsInLine,]
      form = OrdersModelForm
  
  class PointsInLine(NestedStackedInline):
      model = Points
      fk_name = 'order_id'
      inlines = [AddressesInLine]
  
  class AddressesInLine(NestedStackedInline):
      model = Addresses
      fk_name = 'point'
      form = AddressModelForm
  </code></pre>
  
  <p>As you can see I also create a custom form for the last level (<code>AddressesInLine</code>) which looks like this:</p>
  
  <pre><code>class AddressModelForm(forms.ModelForm):
  
      def __init__(self, *args, **kwargs):
          super(forms.ModelForm, self).__init__(*args, **kwargs)
          self.fields['address'].widget = BoxSearchWidget()
  
      class Meta:
          fields = '__all__'
          model = Addresses
  </code></pre>
  
  <p>Again, I am overriding the field 'address' with a custom widget (which I will not include due to simplicity).</p>
  
  <p><strong>Finally, the question is:</strong> when I save, this custom field address is not saved, AND even when I tried to override save() method for the form, I can't see the value in any dictionary. So, <strong>Am I missing something in the creation of the custom form?</strong></p>
  
  <p>Thanks in advance!</p>