Remove unused parameter other in asteroid.destroy()
Remove unused parameter other in asteroid.destroy()

With the parameter, it looked like the method was intended to destroy
the 'other' asteroid only. Actually, the method destroys the current
asteroid and all asteroid in contact (transitively).

matthewsimo/coquette,cdosborn/coquette,maryrosecook/coquette,maryrosecook/coquette,cdosborn/coquette,matthewsimo/coquette