Changes with nginx 1.7.1 27 May 2014

    *) Feature: the "$upstream_cookie_..." variables.

    *) Feature: the $ssl_client_fingerprint variable.

    *) Feature: the "error_log" and "access_log" directives now support
       logging to syslog.

    *) Feature: the mail proxy now logs client port on connect.

    *) Bugfix: memory leak if the "ssl_stapling" directive was used.
       Thanks to Filipe da Silva.

    *) Bugfix: the "alias" directive used inside a location given by a
       regular expression worked incorrectly if the "if" or "limit_except"
       directives were used.

    *) Bugfix: the "charset" directive did not set a charset to encoded
       backend responses.

    *) Bugfix: a "proxy_pass" directive without URI part might use original
       request after the $args variable was set.
       Thanks to Yichun Zhang.

    *) Bugfix: in the "none" parameter in the "smtp_auth" directive; the bug
       had appeared in 1.5.6.
       Thanks to Svyatoslav Nikolsky.

    *) Bugfix: if sub_filter and SSI were used together, then responses
       might be transferred incorrectly.

    *) Bugfix: nginx could not be built with the --with-file-aio option on
       Linux/aarch64.