Modernize VC scripts

Change-Id: I260af56726ba75a56857a5af97c373432d69a910
diff --git a/dev/js/src/vc/prefix.js b/dev/js/src/vc/prefix.js
index 5deefe4..32989bc 100644
--- a/dev/js/src/vc/prefix.js
+++ b/dev/js/src/vc/prefix.js
@@ -1,3 +1,5 @@
+"use strict";
+
 define(['menu/prefix'], function (prefixClass) {
   return {
 
@@ -9,6 +11,7 @@
 	      upgradeTo(this)._init(params);
     },
 
+
     /**
      * Override the prefix action.
      */