Fixed #11413 -- Added notes on the cycle and firstof tag detailing that...

Fixed #11413 -- Added notes on the cycle and firstof tag detailing that variables output by those tags will not be escaped by default. Thanks to krystal for the report and draft patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11163 bcc190cf-cafb-0310-a4f2-bffc1f526a37