Move GardeningServer out of BuildSlaveSupport

Tools/GardeningServer/scripts/PersistentCache.js

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 68 matching lines @@
     },
 
     _parseDateAndJSONFromString: function(string) {
         var separatorIndex = string.indexOf(this._dateAndJSONSeparator);
         return {
             date: new Date(parseInt(string.substring(0, separatorIndex), 10)),
             json: string.substring(separatorIndex + this._dateAndJSONSeparator.length),
         };
     },
 };