Fix sprites not following layer overlapping

[timothymtorres]

The generic_building sprites for the isometric map are overlapping other buildings in the same layer.

This could be something with using the staggered isometric map and it’s not rendering properly. Another possibility is that because the generic_building is a larger size than others (32x63) it breaks the draw order somehow? Or maybe it has something to do with the ordering system being setup alphabetically.