Update from 1.4.4 to bugfix release 1.4.5.

<ChangeLog>

*) Bugfix: the $ssl_session_id variable contained full session

serialized instead of just a session id.
Thanks to Ivan Ristić.

*) Bugfix: client connections might be immediately closed if deferred

accept was used; the bug had appeared in 1.3.15.

*) 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: a timeout might occur while reading client request body in an

SSL connection using chunked transfer encoding.

*) Bugfix: memory leak in nginx/Windows.

</ChangeLog>