Action-231, issue-153 requirements on other software that sets DNT headers

Here is my suggestion for language pursuant to Action 231.

A user agent MUST have a default tracking preference of unset (DNT is not
enabled; no tracking preference signal is sent). A user agent extension or
add-on must not alter the user's tracking preference setting unless it
complies with Section 5 of this document (User Preferences). Software
outside of the user agent that causes a DNT header to be sent (or modifies
existing headers) MUST NOT do so without following the requirements of this
section; such software also MUST ensure the expressed preference reflects
the individual user's intent.

Alan