models: Create class decorator for adding admin objects.
Wrap all models using register_to_admin.
frontend: Register objects using a for loop.
Auth.py, posts.py, users.py: Remove no longer needed admin code.
Update admin/index.html to reflect changes in DB.
Lowercase ADMIN_OBJECTS.

Tie the admin instance to the frontend application
instance in order to registered an authenticated
admin index view that prevents non-webmasters from
viewing the admin console.
Merge branch 'hotfix-admin-register'