Changes with nginx 1.1.18 28 Mar 2012

*) Change: keepalive connections are no longer disabled for Safari by
default.

*) Feature: the $connection_requests variable.

*) Feature: $tcpinfo_rtt, $tcpinfo_rttvar, $tcpinfo_snd_cwnd and
$tcpinfo_rcv_space variables.

*) Feature: the "worker_cpu_affinity" directive now works on FreeBSD.

*) Feature: the "xslt_param" and "xslt_string_param" directives.
Thanks to Samuel Behan.

*) Bugfix: in configure tests.
Thanks to Piotr Sikora.

*) Bugfix: in the ngx_http_xslt_filter_module.

*) Bugfix: nginx could not be built on Debian GNU/Hurd.