T_MEMTHING [0 to 255] [0 to 255] [0 to 255]
Add to selected thing's memory of things on map thing of ID of first argument,
y position of second argument and x position of third argument.
T_MEMTHING [0 to 255] [0 to 255] [0 to 255]
Add to selected thing's memory of things on map thing of ID of first argument,
y position of second argument and x position of third argument.