Upgrade from 1.11.2 to 1.11.3.

<ChangeLog>

*) Change: now the "accept_mutex" directive is turned off by default.

*) Feature: now nginx uses EPOLLEXCLUSIVE on Linux.

*) Feature: the ngx_stream_geo_module.

*) Feature: the ngx_stream_geoip_module.

*) Feature: the ngx_stream_split_clients_module.

*) Feature: variables support in the "proxy_pass" and "proxy_ssl_name"

directives in the stream module.

*) Bugfix: socket leak when using HTTP/2.

*) Bugfix: in configure tests.

Thanks to Piotr Sikora.

</ChangeLog>