Changes with nginx 1.5.1 04 Jun 2013

*) Feature: the "ssi_last_modified", "sub_filter_last_modified", and
"xslt_last_modified" directives.
Thanks to Alexey Kolpakov.

*) Feature: the "http_403" parameter of the "proxy_next_upstream",
"fastcgi_next_upstream", "scgi_next_upstream", and
"uwsgi_next_upstream" directives.

*) Feature: the "allow" and "deny" directives now support unix domain
sockets.

*) Bugfix: nginx could not be built with the ngx_mail_ssl_module, but
without ngx_http_ssl_module; the bug had appeared in 1.3.14.

*) Bugfix: in the "proxy_set_body" directive.
Thanks to Lanshun Zhou.

*) Bugfix: in the "lingering_time" directive.
Thanks to Lanshun Zhou.

*) Bugfix: the "fail_timeout" parameter of the "server" directive in the
"upstream" context might not work if "max_fails" parameter was used;
the bug had appeared in 1.3.0.

*) Bugfix: a segmentation fault might occur in a worker process if the
"ssl_stapling" directive was used.
Thanks to Piotr Sikora.

*) Bugfix: in the mail proxy server.
Thanks to Filipe Da Silva.

*) Bugfix: nginx/Windows might stop accepting connections if several
worker processes were used.