fixed standalone graph controls not working

fix for https://jira.zenoss.com/browse/ZEN-12297

standalone graphs were loading config file from a base64 encoded json string, and that string included some Extjs stuff that didn't belong there. This caused the graph controls to be initialized without handler functions, so the buttons, they do naaathing!

Added a sort of blacklist for the json serialization, and found and fixed an instance of a local var `now` shadowing a closure function `now()`.