title: Registering the same model in different configurations for different apps with Django admin
body: <p>I have a rather large CMS with many modules and am regulating access with Django permissions.  Each app has a UserProfile model with a User object as a ForeignKey.  I want to be able to allow easy lookup and creation of UserProfile objects within each app.  I wanted to use Inlines to do it like this (from project/app/admin.py):</p>
  
  <pre><code>class InlineModelForUser(admin.TabularInline):
      model = User
      extra=0
  
  class UserSettings(admin.ModelAdmin):
      search_fields = ['username', 'name']
      readonly_fields = ['username','name', 'otherproperites']
      inlines = [InlineModelForUser,]
  
  admin.site.register(User, UserSettings)
  </code></pre>
  
  <p>Error returned is:"The model User is already registered".  I understand why it's happening and I appreciate that I can probably implement the same functionality in a different way.  What I am trying to achieve is segregate the editing of the base object (User) and the app profile object attached.  I see of course that I can make an autocomplete field in the CreateView for the UserProfile, but sometimes you need to provide different filtering tools for each app (filtering for/against User properties) AND the need to hide some user information from the users of each app.</p>
  
  <p>Basically: How can I within the django.contrib.admin build several views against the same model and register it with admin.site.register?</p>