Model 2 Emulator "1.0 / 0.10 / 0.91" WIP

Emulated a rarely used feature of the model2 tilemaps:

Before:

Now:

Is so rare that I don't know any other place where it's used . It will eat the fillrate of drawing an extra tilemap, but shouldn't be noticeable on any videocard (just 2 extra polygons covering all screen)