Chrome extension - unique ID

I've fix some points :
- Unique ID for extension version by day ( limitation due to the version rules of Chrome Extensions .. )
- allow offline mode
- ignore manifest.json from hawtio-web to use the chrome-extension one's

I've also try to upload the generated zip on the store to check :
https://chrome.google.com/webstore/detail/hawtio/nhhciclhhmgoebceacocjfbdojbmihlf

I don't have put the http://**/* permisions... but it's working for me with external jolokia.
Give a try :

Scheme : http
Host : jolokia-remote.latibox.cloudbees.net
Path : /
Port : 80