I added sprites - now some games became playable!

There is an off by one error both horizontally and vertically in the drawing system, and no support for sprites bleeding in from the left side of the screen, and only 16x16 unscaled sprites are supported - but who cares as TI Invaders now is playable! (If we ignore that it runs at times too fast). The picture below is not great, I took with my phone not proper camera, sorry about that.