Moved all configurations away from $GLOBALS to independent variables

lib/php/management/logout.php

@@ -1,3 +1,3 @@
 <?php
     $_SESSION [ 'user_id' ] = NULL;
-    header ( "Location: " . substr ( $_SERVER [ 'SCRIPT_NAME' ], 0, -10 ) . "/" );
+    header ( "Location: " . $config [ 'installation_path' ] . "/" );