title: Django Admin: Default values in StackedInline / TabularInline
body: <p>I'm creating a website and it needs support for internationalization. The default languages are Portuguese, English and Spanish. I'm using the django-i18nmodel and so far it works great.</p>
  
  <p>When the admin wants to create a product, using django-admin, by default I create 3 inLine items of the model ProductI18N. </p>
  
  <pre><code>class LanguageStackedInline(admin.StackedInline):
      model = ProductI18N
      extra = 1
  </code></pre>
  
  <p>I want to create these 3 rows with the <strong>3</strong> default languages I mentioned above (pt-PT, en-US, es-ES). I know that in the Model I can only set a default value.</p>
  
  <p>Does Django provide an easy way of doing this?</p>