Internal resolution scale and support for maximizing the game window

[land of dran kino agent]

allow maximizing the window and dynamic resolutions.

Also maybe a slider on the options menu that allows you to render the game at a lower resolution or a way to directly set the frame size. Example: Rendering at 1280x720 or 640x360 while the game window is 1920x1080 - not affecting UI. Would be helpful for those with poorer GPU's.