title: Assigning a group while adding user in django-admin
body: <p>In my application, I have models that have the Users model as a Foreign key, eg:</p>
  
  <pre><code>class Doctor(models.Model):    
  username=models.ForeignKey(User, unique=True)
  ...
  </code></pre>
  
  <p>In the admin site, when adding a new Doctor, I have the option of adding a new User next to the username field. This is exactly what I want, but in the dialog that opens, it asks for a username and password for the new user; I would also like to be able to assign a group to this new user. What would be the best way of doing this ?</p>
  
  <p>Thanks,
  lokharkey</p>