Privacy Panel new pull request

This is a new pull request. We had to remove the old one due to big problems with git and some Schroedinger patches....
You will need to require it first before using : https://github.com/mozilla-b2g/gaia/blob/bf1a629614c9454117e96002284cd0878b4c94ac/apps/settings/js/panels/root/themes_item.js#L10