Changes with nginx 1.3.16 16 Apr 2013

*) Bugfix: a segmentation fault might occur in a worker process if
subrequests were used; the bug had appeared in 1.3.9.

*) Bugfix: the "tcp_nodelay" directive caused an error if a WebSocket
connection was proxied into a unix domain socket.

*) Bugfix: the $upstream_response_length variable has an incorrect value
"0" if buffering was not used.
Thanks to Piotr Sikora.

*) Bugfix: in the eventport and /dev/poll methods.