Changes with nginx 1.9.0 28 Apr 2015
*) Change: obsolete aio and rtsig event methods have been removed.
*) Feature: the "zone" directive inside the "upstream" block.
*) Feature: the stream module.
*) Feature: byte ranges support in the ngx_http_memcached_module. Thanks to Martin Mlynář.
*) Feature: shared memory can now be used on Windows versions with address space layout randomization. Thanks to Sergey Brester.
*) Feature: the "error_log" directive can now be used on mail and server levels in mail proxy.
*) Bugfix: the "proxy_protocol" parameter of the "listen" directive did not work if not specified in the first "listen" directive for a listen socket.