[-] Add a new option in admin preference to recompile smarty templates only when they are updated

config/defines.inc.php

@@ -151,3 +151,7 @@ define('_PS_GEOLOCATION_NO_ORDER_', 1);
 
 if (!defined('_PS_CACHE_ENABLED_'))
     define('_PS_CACHE_ENABLED_', 0);
+
+define('_PS_SMARTY_NO_COMPILE_', 0);
+define('_PS_SMARTY_CHECK_COMPILE_', 1);
+define('_PS_SMARTY_FORCE_COMPILE_', 2);