QNetworkAccessManager should handle all informational HTTP replies

QNetworkAccessManager currently skips only "100 Continue" informational replies from HTTP servers. It does report other information replies as final results. This contradicts RFC 2616:

A client MUST be prepared to accept one or more 1xx status responses
prior to a regular response, even if the client does not expect a 100
(Continue) status message. Unexpected 1xx status responses MAY be
ignored by a user agent.

Ideally such informational responses would be reported to user somehow. Just discarding them all is fine too.