wumpus-basic

Update: The PosGraphic type was wrong, it has been rectified but the composition operators have been dropped as they used 'introspection' that the corrected type does not support.

Copperbox revision 2095.

I've replaced PosImage with a simpler object - PosGraphic. My intention is that PosGraphic should also supersede Bounded and possibly AdvanceGraphic.

PosGraphic is in progress, but it should be able to support picture language like operations once I have added a semigroup instance.