title: Implementing an inline to represent a ListField in Django-nonrel
body: <p>Is it possible to use something similar to the inline relational items from the Django admin to represent embedded models in a ListField?  </p>
  
  <p>For Example, I've got the following models:</p>
  
  <pre><code>class CartEntry(model.Model):
      product_name=model.CharField( max_length=20 )
      quantity = model.IntegerField()
  
  class Cart(model.Model):
      line_items = ListField(EmbeddedModelField('CartEntry'))
  </code></pre>
  
  <p>I've tried using the standard inlining, but I know it's not right:</p>
  
  <pre><code>class CartEntryInline( admin.StackedInline ):
      model=CartEntry
  
  class CartAdmin(admin.ModelAdmin)
      inlines=[CartEntryInline]
  </code></pre>
  
  <p>But obviously that doesn't work, since there's no foreign key relation.  Is there any way to do this in django-nonrel?</p>