#8 Support Fullscreen/Windowed Mode Toggle

[Ekkehard Morgenstern]

Currently, THE ENGINE is always running in full-screen mode. There should be a mechanism to switch between full-screen and windowed mode. Also: Window sizing support, window maximization / minimization. Also, THE ENGINE should switch to windowed mode if it loses focus. This prevents problems if the desktop system tries to notify the user of something and takes away focus. Alt-TAB should minimize the application or communicate with the desktop in some way to let the window switcher appear. Currently, Alt-TAB is a no-op. Handling these issues would also allow users to run multiple instances of THE ENGINE in multiple windows.