Avoid using a unique key for keyPrefix as it causes issues when lodash is modularized into individual npm packages. [closes #446]

lodash.js

@@ -22,7 +22,7 @@
   var indicatorObject = {};
 
   /** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */
-  var keyPrefix = +new Date + '';
+  var keyPrefix = '__1335248838000__';
 
   /** Used as the size when optimizations are enabled for large arrays */
   var largeArraySize = 75;