Bug 1067614 - [User Story] Ensure users are always on the latest loop mo...

...bile version
Please note that app.download() does *NOT* apply the downloaded file once it's downloaded. And applying the download is a certified app only operation (it lives on the mozApps.mgmt object). So the user would still need to go to the... whatever the name of the curtain screen is and apply the download from there.

And probably we should inform him of this.