Changes with nginx 1.5.9 22 Jan 2014
*) Change: now nginx expects escaped URIs in "X-Accel-Redirect" headers.
*) Feature: the "ssl_buffer_size" directive.
*) Feature: the "limit_rate" directive can now be used to rate limit responses sent in SPDY connections.
*) Feature: the "spdy_chunk_size" directive.
*) Feature: the "ssl_session_tickets" directive. Thanks to Dirkjan Bussink.
*) Bugfix: the $ssl_session_id variable contained full session serialized instead of just a session id. Thanks to Ivan Ristić.
*) Bugfix: nginx incorrectly handled escaped "?" character in the "include" SSI command.
*) Bugfix: the ngx_http_dav_module did not unescape destination URI of the COPY and MOVE methods.
*) Bugfix: resolver did not understand domain names with a trailing dot. Thanks to Yichun Zhang.
*) Bugfix: alerts "zero size buf in output" might appear in logs while proxying; the bug had appeared in 1.3.9.
*) Bugfix: a segmentation fault might occur in a worker process if the ngx_http_spdy_module was used.
*) Bugfix: proxied WebSocket connections might hang right after handshake if the select, poll, or /dev/poll methods were used.
*) Bugfix: the "xclient" directive of the mail proxy module incorrectly handled IPv6 client addresses.