Upgrade from 1.11.5 to 1.11.6.

Mark following third-party modules with IGNORE, a patches require from upstreams:
o) http_upstream_fair;
o) drizzle;
o) memc;
o) postgres;
o) redis2.

<ChangeLog>

*) Change: format of the $ssl_client_s_dn and $ssl_client_i_dn variables

has been changed to follow RFC 2253 (RFC 4514); values in the old
format are available in the $ssl_client_s_dn_legacy and
$ssl_client_i_dn_legacy variables.

*) Change: when storing temporary files in a cache directory they will

be stored in the same subdirectories as corresponding cache files
instead of a separate subdirectory for temporary files.

*) Feature: EXTERNAL authentication mechanism support in mail proxy.

Thanks to Robert Norris.

*) Feature: WebP support in the ngx_http_image_filter_module.

*) Feature: variables support in the "proxy_method" directive.

Thanks to Dmitry Lazurkin.

*) Feature: the "http2_max_requests" directive in the

ngx_http_v2_module.

*) Feature: the "proxy_cache_max_range_offset",

"fastcgi_cache_max_range_offset", "scgi_cache_max_range_offset", and
"uwsgi_cache_max_range_offset" directives.

*) Bugfix: graceful shutdown of old worker processes might require

infinite time when using HTTP/2.

*) Bugfix: in the ngx_http_mp4_module.

*) Bugfix: "ignore long locked inactive cache entry" alerts might appear

in logs when proxying WebSocket connections with caching enabled.

*) Bugfix: nginx did not write anything to log and returned a response

with code 502 instead of 504 when a timeout occurred during an SSL
handshake to a backend.

</ChangeLog>