*) Change: now responses from proxied servers over HTTP/0.9 are rejected
   as invalid by default; the "proxy_allow_http09" directive allows
   processing of such responses.

*) Change: stricter syntax checks are now applied to the "Host" request
   header line.

*) Feature: now interim 1xx responses of proxied servers are ignored.

*) Feature: certificates for IP addresses are now supported when
   verifying backend SSL certificates.

*) Feature: the "proxy_allow_duplicate_chunked" directive.
   Thanks to Gennady Bekasov.

*) Bugfix: when using a host name in the request line, the "_" and some
   other characters were not allowed, as well as zone identifiers in
   IPv6 addresses.

*) Workaround: "shutdown() failed (22: Invalid argument)" alerts might
   appear in logs on NetBSD.

*) Bugfix: in the mail proxy module.