Fixed #6265 -- Added an example of overriding a form field's default widget in...

Fixed #6265 -- Added an example of overriding a form field's default widget in the modelforms docs, based on patch from programmerq.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@7036 bcc190cf-cafb-0310-a4f2-bffc1f526a37