Bug 1058459 - [SMS] Data shared from other applications are not shown as Drafts until the app is killed and open again.  r=schung

Using localStorage as inter app communication bus.
Well, seems ```onbeforeunload``` doesn't work at all(https://bugzilla.mozilla.org/show_bug.cgi?id=996754) and ```onunload``` isn't always fired when app is killed from task manager :(