Misc fixes and improvements

Today's patch has some fixes and improvements:

• Alt+Enter now toggles between full screen and windowed mode

• F11 full screen toggle hotkey now works at the profile selection screen

• Rules can now be shown in the game window or in a separate window (new setting)

• Added a column to the free play grid that shows whether or not a variant has an in-progress saved game

• Drastically reduced memory usage of game