Changes with nginx 0.5.19 24 Apr 2007

    *) Change: now the $request_time variable has millisecond precision.

    *) Change: the method $r->rflush of ngx_http_perl_module was renamed to
       the $r->flush.

    *) Feature: the $upstream_addr variable.

    *) Feature: the "proxy_headers_hash_max_size" and
       "proxy_headers_hash_bucket_size" directives.
       Thanks to Volodymyr Kostyrko.

    *) Bugfix: the files more than 2G could not be transferred using
       sendfile and limit_rate on 64-bit platforms.

    *) Bugfix: the files more than 2G could not be transferred using
       sendfile on 64-bit Linux.