Bug 1069915 - Privacy Panel

This is a new pull regrets for the Privacy Panel. I am very sorry to open another pull request instead of reopening the old one, but before I thought twice I have deleted my mold branch and had to reopen everything from the beginning. 
So in `launch` method, there is one thing left - `this._privacyPanelApp` and you just have to check whether this variable is null or not and then lunch it.