Dynamic script use for different cubes (I think)

Got dynamic script selection for different cubes working. (I think)  If
this all works, cubes should now be able to have their own scripts for
defining their growth and shrinking behavior.  I will test later.
Double cube added and tested

Added the double cube, which creates two cubes with the grow command
instead of one.  Tested and the new action calling system works.  The
player script can trigger the grow & shrink actions on any cube that
inherits from the abstract cube class without haveing to know the
specific script it is triggering.