Changes with nginx 1.5.7 19 Nov 2013

*) Security: a character following an unescaped space in a request line
was handled incorrectly (CVE-2013-4547); the bug had appeared in
0.8.41.
Thanks to Ivan Fratric of the Google Security Team.

*) Change: a logging level of auth_basic errors about no user/password
provided has been lowered from "error" to "info".

*) Feature: the "proxy_cache_revalidate", "fastcgi_cache_revalidate",
"scgi_cache_revalidate", and "uwsgi_cache_revalidate" directives.

*) Feature: the "ssl_session_ticket_key" directive.
Thanks to Piotr Sikora.

*) Bugfix: the directive "add_header Cache-Control ''" added a
"Cache-Control" response header line with an empty value.

*) Bugfix: the "satisfy any" directive might return 403 error instead of
401 if auth_request and auth_basic directives were used.
Thanks to Jan Marc Hoffmann.

*) Bugfix: the "accept_filter" and "deferred" parameters of the "listen"
directive were ignored for listen sockets created during binary
upgrade.
Thanks to Piotr Sikora.

*) Bugfix: some data received from a backend with unbufferred proxy
might not be sent to a client immediately if "gzip" or "gunzip"
directives were used.
Thanks to Yichun Zhang.

*) Bugfix: in error handling in ngx_http_gunzip_filter_module.

*) Bugfix: responses might hang if the ngx_http_spdy_module was used
with the "auth_request" directive.

*) Bugfix: memory leak in nginx/Windows.