Changes with nginx 0.5.9 25 Jan 2007

    *) Change: now the ngx_http_memcached_module uses the $memcached_key
       variable value as a key.

    *) Feature: the $memcached_key variable.

    *) Feature: the "clean" parameter in the "client_body_in_file_only"
       directive.

    *) Feature: the "env" directive.

    *) Feature: the "sendfile" directive is available inside the "if" block.

    *) Feature: now on failure of the writing to access nginx logs a
       message to error_log, but not more often than once a minute.

    *) Bugfix: the "access_log off" directive did not always turn off the
       logging.