A modified patch from Gareth Carter for "JSON Response does not set http status on error" https://issues.apache.org/jira/browse/OFBIZ-5409

This is rather a defensive patch which secure json response on services calls. 
It might need some changes in custom code if (not recommended) an Ajax GET response is used... The util.js scrpt is introduced for that, though normally should not be needed... 

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1557462 13f79535-47bb-0310-9956-ffa450edef68