title: Copy all fields of a django model instance
body: <p>ok i think this is very basic, but since I am new to Django I don't know how to handle this.</p>
  
  <p>I need to copy an instance of a django-model. As explained <a href="http://code.djangoproject.com/ticket/4027" rel="nofollow">here</a>, there is a problem with copying ManyToMany relations. But the attachment "django-model-copying.diff" has that function I guess. So I don't know - does my Django already have that function? I don't know how to call it.
  Help would be appreciated.</p>