title: Django Migration Modify Inherited Default
body: <p>I have a model class in Django <code>Parent</code> with a subclass <code>Child</code>. Parent has a boolean field <code>foo</code> which defaults to <code>True</code> that Child inherited. I'd like to migrate my Child class so that</p>
  <ol>
  <li>All new Child objects have a default of False for the foo field</li>
  <li>All existing Child objects have the foo field set to False</li>
  </ol>
  <p>How can I achieve this in Django?</p>