add basic mobile user detection

index.php

@@ -82,6 +82,10 @@ reloadSettings();
 cleanRequest();
 $context = array();
 
+include("Mobile_Detect.php");
+$detect = new Mobile_Detect();
+define('MOBILE', $detect->isMobile());
+
 // Determine if this is should be using WAP, WAP2, or imode.
 define('WIRELESS', isset($_REQUEST['wap']) || isset($_REQUEST['wap2']) || isset($_REQUEST['imode']));