make 'JSON' scope local

Author: minodisk

deps/json2.js

@@ -159,9 +159,7 @@
 // Create a JSON object only if one does not already exist. We create the
 // methods in a closure to avoid creating global variables.
 
-if (!this.JSON) {
-    this.JSON = {};
-}
+var JSON = {};
 
 (function () {
     "use strict";