Move the Python 2.5 specific tests out of their own special files now that 2.5...

Move the Python 2.5 specific tests out of their own special files now that 2.5 is the default.  Also add __futre__ import where necessary.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15935 bcc190cf-cafb-0310-a4f2-bffc1f526a37