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.

When "debug_connection" is configured with a domain name, only the first
resolved address was used.  Now all addresses will be used.

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.

If ngx_spawn_process() failed while starting a process, the process
handle was closed but left non-NULL in the ngx_processes[] array.
The handle later was used in WaitForMultipleObjects() (if there
were multiple worker processes configured and at least one worker
process was started successfully), resulting in infinite loop.

Reported by Ricardo Villalobos Guevara:
http://mailman.nginx.org/pipermail/nginx-devel/2012-July/002494.html

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