Display release after updates are installed

[floatas]

Currently all updates are installed silently. How it should work:

1. Updates are installed
2. When closes application
3. Opens application (new version will be started)
4. New windows opens with release notes (but only once).
5. Older release notes maybe displayed in about page ?

To make implementation easier, it might be enough to download release note html and display it browser control.

Release notes can be pulled from https://github.com/YetAnotherPomodoroApp/YAPA-2/releases and using tags: https://github.com/YetAnotherPomodoroApp/YAPA-2/releases/tag/v2.0.80