Allow a local config file

.gitignore

+/config.inc.php

www/index.php

 <?php
 
-require_once dirname(__FILE__).'/../config.sample.php';
+$config_file = __DIR__ . '/../config.sample.php';
+
+if (file_exists(__DIR__ . '/../config.inc.php')) {
+    $config_file = __DIR__ . '/../config.inc.php';
+}
+require_once $config_file;
 
 UNL_Templates::setCachingService(new UNL_Templates_CachingService_Null());