- reengineering st-yinyang:
- st-yinyang1 -> st_blur_cross
- st-yinyang2 -> st_blur_straight
- st-yinyang3 -> st_blur_magic
- attribute flavor with type name "cross", "straight", "magic"
- new graphic indicating color change instead of player change
- reengineering grates:
- st-grate1 -> st_grate_cross
- st-grate2 -> st_grate_framed
- attribute flavor with type name "cross", "framed"