The ngx_http_find_virtual_server() function should return NGX_DECLINED
if virtual server not found.

Hide headers and pass headers arrays might not be inherited correctly
into a nested location, e.g. in configuration like

    server {
        proxy_hide_header X-Foo;
        location / {
            location /nested/ {
                proxy_pass_header X-Pad;
            }
        }
    }

the X-Foo header wasn't hidden in the location /nested/.

Reported by Konstantin Svist,
http://mailman.nginx.org/pipermail/nginx-ru/2012-July/047555.html

*) Fixed to return NULL if an error occurs.

*) Microoptimization: replaced an expression known to be constant with
   the constant value.

Fixed compilation with -Wmissing-prototypes.  Added a commented
out -Wmissing-prototypes to CFLAGS.  It is commented out to not break
builds with 3rd party modules.

Fixed debugging messages to account that limit_zone was renamed to limit_conn.

Fixed sorting of listen addresses so that wildcard address is always at
the end.  Failure to do so could result in several listen sockets to be
created instead of only one listening on wildcard address.

Reported by Roman Odaisky.

Reset r->uri_changed in a named location (ticket #184).