Uses a modified method suggested bythis comment by @alexmercerind, which in general reduces flicker when going to full screen and just behaves more predictable.

Todo:

• Remove unused code.
• Add comments .

HowsetFullScreen(true) works now

1. Native window title bar is removed.
2. Remove/hide custom title bar widget (Developers should do this themselves).
3. Borders (including the rounded corners) are removed
4. Window is maximized to fit the whole screen.
5. Prevent the user from resizing the window (disablesstartResizing())
6. Prevent the user from dragging/moving the window (disablesstartDragging())