Fixed #12804 - regression with decorating admin views.

This is a BACKWARDS INCOMPATIBLE change, because it removes the flawed
'auto_adapt_to_methods' decorator, and replaces it with 'method_decorator'
which must be applied manually when necessary, as described in the 1.2
release notes.

For users of 1.1 and 1.0, this affects the decorators:

 * login_required
 * permission_required
 * user_passes_test

For those following trunk, this also affects:

 * csrf_protect
 * anything created with decorator_from_middleware 

If a decorator does not depend on the signature of the function it is
supposed to decorate (for example if it only does post-processing of the
result), it will not be affected.
 



git-svn-id: http://code.djangoproject.com/svn/django/trunk@12399 bcc190cf-cafb-0310-a4f2-bffc1f526a37