Changes with nginx 0.7.55 06 May 2009

    *) Bugfix: the http_XXX parameters in "proxy_cache_use_stale" and
       "fastcgi_cache_use_stale" directives did not work.

    *) Bugfix: fastcgi cache did not cache header only responses.

    *) Bugfix: of "select() failed (9: Bad file descriptor)" error in
       nginx/Unix and "select() failed (10022: ...)" error in nginx/Windows.

    *) Bugfix: a segmentation fault might occur in worker process, if an
       "debug_connection" directive was used; the bug had appeared in
       0.7.54.

    *) Bugfix: fix ngx_http_image_filter_module building errors.

    *) Bugfix: the files bigger than 2G could not be transferred using
       $r->sendfile.
       Thanks to Maxim Dounin.