[1.1.X] Fixed #13093 -- Updated some decorators and the...

[1.1.X] Fixed #13093 -- Updated some decorators and the decorator_from_middleware function to allow callable classes to be decorated. Thanks to Brian Neal for the report.

Backport of r12762 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@12763 bcc190cf-cafb-0310-a4f2-bffc1f526a37