Fixed #6927: Corrected documentation describing when and why the auth...

Default permissions

-------------------

Three basic permissions -- add, change and delete -- are automatically created

for each Django model that has a ``class Admin`` set. Behind the scenes, these

permissions are added to the ``auth_permission`` database table when you run

``manage.py syncdb``.

Note that if your model doesn't have ``class Admin`` set when you run

``syncdb``, the permissions won't be created. If you initialize your database

and add ``class Admin`` to models after the fact, you'll need to run

``manage.py syncdb`` again. It will create any missing permissions for

all of your installed apps.

When ``django.contrib.auth`` is listed in your ``INSTALLED_APPS``

setting, it will ensure that three default permissions -- add, change

and delete -- are created for each Django model defined in one of your

installed applications.

These permissions will be created when you run ``manage.py syncdb``;

the first time you run ``syncdb`` after adding ``django.contrib.auth``

to ``INSTALLED_APPS``, the default permissions will be created for all

previously-installed models, as well as for any new models being

installed at that time. Afterward, it will create default permissions

for new models each time you run ``manage.py syncdb``.

Custom permissions

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