Update "Support for different screen ratios"

Hi everyone, in this update we've done the following:

• Added support for 4:3 to 16:9 aspect ratio screens

• Added the ability to resize the window in game window mode on aspect ratios from 4:3 to 16:9.

• Windowed game window size is now remembered and used correctly on startup

• Alt+Enter can now be used to toggle between full screen and windowed mode.