Improve how Updates are handled

[casaout]

• [ ] Not forced updates should show a Toast Notification instead of a MessageBox (Problem here is to handle multiple click events of BalloonTips: http://stackoverflow.com/questions/34956678/handling-click-events-of-multiple-taskbaricon-showballoontips)
• [ ] Forced Updates should (maybe) just be installed
• [ ] check for updates in settings/menu?

[tzimmermsr]

Maybe a "Check for updates" menu item

[casaout]

Closing as reported for legacy version of PersonalAnalytics.