Changes with nginx 1.7.4 05 Aug 2014

    *) Security: pipelined commands were not discarded after STARTTLS
       command in SMTP proxy (CVE-2014-3556); the bug had appeared in 1.5.6.
       Thanks to Chris Boulton.

    *) Change: URI escaping now uses uppercase hexadecimal digits.
       Thanks to Piotr Sikora.

    *) Feature: now nginx can be build with BoringSSL and LibreSSL.
       Thanks to Piotr Sikora.

    *) Bugfix: requests might hang if resolver was used and a DNS server
       returned a malformed response; the bug had appeared in 1.5.8.

    *) Bugfix: in the ngx_http_spdy_module.
       Thanks to Piotr Sikora.

    *) Bugfix: the $uri variable might contain garbage when returning errors
       with code 400.
       Thanks to Sergey Bobrov.

    *) Bugfix: in error handling in the "proxy_store" directive and the
       ngx_http_dav_module.
       Thanks to Feng Gu.

    *) Bugfix: a segmentation fault might occur if logging of errors to
       syslog was used; the bug had appeared in 1.7.1.

    *) Bugfix: the $geoip_latitude, $geoip_longitude, $geoip_dma_code, and
       $geoip_area_code variables might not work.
       Thanks to Yichun Zhang.

    *) Bugfix: in memory allocation error handling.
       Thanks to Tatsuhiko Kubo and Piotr Sikora.