[1.2.X] Fixed #15491 -- Added a CDATA block and closed a stray tag in the...

[1.2.X] Fixed #15491 -- Added a CDATA block and closed a stray tag in the comments HTML. Thanks to Jonathan Slenders for the report.

Backport of r15642 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15644 bcc190cf-cafb-0310-a4f2-bffc1f526a37