||This class represents one creature on the board.
||This class represents one Darwin instruction.
||A Position is an (x,y) coordinate in the World, much like
the Positions for the maze program.
||The individual creatures in the world are all representatives of
some species class and share certain common characteristics, such
as the species name and the program they execute.
||This module includes the functions necessary to keep track of the
creatures in a two-dimensional world.
||This class exports the methods necessary to display the creatures
on the screen.