[Interest] Relaunch to Install

[Joshua Kolden]

Many applications have this functionality now, but a good example is the Spotify client.  

The app discovers there is a new version available, downloads it in the background then prompts the user to restart to get the new version. When the user quits the new version is installed (or the installed version is patched) then the application is restarted, all without further user interaction.  In fact, the user really doesn't even have to do anything the app would automatically update on every exit if the user was never notified. 

We have a cross-platform Qt 5.3 application and our lean startup business model requires us to push application updates very often so I'd really like to find a method that works cross platform with as little platform specific code as possible. 

Thanks,
j