Fixed #2102 -- Template system 'for' loops now support generators. Thanks,...

Fixed #2102 -- Template system 'for' loops now support generators. Thanks, dbm-django@mclachlan.com.au

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3165 bcc190cf-cafb-0310-a4f2-bffc1f526a37