wumpus-basic

Copperbox revision 2102.

Bad news - I had seriously over-estimated the worth of the new PosGraphic type. The demos so far always used a "context-free" initial rectangle, as they were drawing rectangles the frame rectangle just took the same dimensions as the drawing. However, text isn't context-free in Wumpus-Basic - font size information is taken from the drawing context - and I realized today that PosGraphic would only ever work with context-free dimensions making it incompatible with text its the most important use-case.

I've rectified this now, but the change has the serious consequence that the new PosGraphic (and its more general version PosImage) cannot support composition operators. This means the last two days work is effectively lost.