don't say 404 Not Found if that is not really what the server said

[jidanni@xxxxxxxxxxx]

Here is a problem that affects emacs-w3m but not w3m.

It the user is using something like WWWOFFLE, and WWWOFFLE is offline,
not every 404 message is "Not Found".
Some are HTTP/1.0 404 WWWOFFLE Will Get
alas emacs-w3m decides on its own that it should be
404 Not Found
and prints that anyway, scaring the user.
Or at most just say "404 (Not Found)".

Location: http://developers.facebook.com/blog/
Cannot retrieve URL: http://developers.facebook.com/blog/

404 Not Found

--------------------------------------------------------------------------------------------------------------------------

                                    WWWOFFLE - World Wide Web Offline Explorer - v2.9h
--------------------------------------------------------------------------------------------------------------------------

                                                WWWOFFLE Request Recorded

                                                   Your request for URL

                                           http://developers.facebook.com/blog/

                                             has been recorded for download.
                                     [Refresh:Options|Monitor|Delete|Index|Configure]
--------------------------------------------------------------------------------------------------------------------------
                                         WWWOFFLE - [Welcome Page|FAQ] - WWWOFFLE

--------------------------------------------------------------------------------------------------------------------------

Header information

W3m-current-url: http://developers.facebook.com/blog/
W3m-document-charset: US-ASCII  <--- weird also...
HTTP/1.0 404 WWWOFFLE Will Get
Server: WWWOFFLE/2.9h
Date: Wed, 19 Jun 2013 19:00:29 GMT
Content-type: text/html
Connection: close
Proxy-Connection: close