Set various proxy headers in nginx config

These headers are required for apps like wordpress to figure the
site url. It is not clear why they do not just use relative urls.

http://cmanios.wordpress.com/2014/04/12/nginx-https-reverse-proxy-to-wordpress-with-apache-http-and-different-port/

nginx/appconfig.ejs

@@ -17,6 +17,16 @@ server {
     }
     location / {
         proxy_pass http://127.0.0.1:<%= port %>;
+
+        proxy_read_timeout       3500;
+        proxy_connect_timeout    3250;
+
+        proxy_set_header   Host               $host;
+        proxy_set_header   X-Originating-IP   $remote_addr;
+        proxy_set_header   X-Forwarded-For    $remote_addr;
+        proxy_set_header   X-Forwarded-Host   $host;
+
+        proxy_set_header   X-Forwarded-Proto  https;
     }
 }