[patch] Cleaning the newforms fields `clean` methods
|Reported by:||SmileyChris||Owned by:||adrian|
|Cc:||Triage Stage:||Ready for checkin|
|Has patch:||yes||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
Small patch to clean up some inconsistencies with the clean methods of fields in newforms.
(an outstanding inconsistency that I did not address in this patch is that sometimes super(fieldname, self).clean is used, other times Field.clean is used)