CD-I version now has a text layer and sprites

I got the text layer and sprites working on the CD-I. I still need to test it out to ensure it does correctly erase the sprites and text. This will require user input, which is next on the agenda. I may still need to optimize the routines, but I'm going to wait until the game is running before I make a determination on that.

The updated version is on the CD-I page (http://frogfeast.rastersoft.net/CDI.html). The demo zip contains the current version. In the next day or two, I should have user input working, and the game screen showing.