Changes with nginx 1.9.4 18 Aug 2015
*) Change: the "proxy_downstream_buffer" and "proxy_upstream_buffer"
directives of the stream module are replaced with the
*) Feature: the "tcp_nodelay" directive in the stream module.
*) Feature: multiple "sub_filter" directives can be used simultaneously.
*) Feature: variables support in the search string of the "sub_filter"
*) Workaround: configuration testing might fail under Linux OpenVZ.
Thanks to Gena Makhomed.
*) Bugfix: old worker processes might hog CPU after reconfiguration with
a large number of worker_connections.
*) Bugfix: a segmentation fault might occur in a worker process if the
"try_files" and "alias" directives were used inside a location given
by a regular expression; the bug had appeared in 1.7.1.
*) Bugfix: the "try_files" directive inside a nested location given by a
regular expression worked incorrectly if the "alias" directive was
used in the outer location.
*) Bugfix: in hash table initialization error handling.
*) Bugfix: nginx could not be built with Visual Studio 2015.