Fixed #18023 -- Removed bundled simplejson.

And started the deprecation path for django.utils.simplejson.

Thanks Alex Ogier, Clueless, and other contributors for their
work on the patch.

formtools/wizard/storage/cookie.py

@@ -1,6 +1,7 @@
+import json
+
 from django.core.exceptions import SuspiciousOperation
 from django.core.signing import BadSignature
-from django.utils import simplejson as json
 
 from django.contrib.formtools.wizard import storage