Changes with nginx 1.1.4 20 Sep 2011

*) Feature: the ngx_http_upstream_keepalive module.

*) Feature: the "proxy_http_version" directive.

*) Feature: the "fastcgi_keep_conn" directive.

*) Feature: the "worker_aio_requests" directive.

*) Bugfix: if nginx was built --with-file-aio it could not be run on
Linux kernel which did not support AIO.

*) Bugfix: in Linux AIO error processing.
Thanks to Hagai Avrahami.

*) Bugfix: reduced memory consumption for long-lived requests.

*) Bugfix: the module ngx_http_mp4_module did not support 64-bit MP4
"co64" atom.