Wumpus

Copperbox revision 891.

I've made a minor tweak to the Path data type so that it isn't attributed with a drawing style (Fill, Stroke, ...). This is in line with the previous change that made a distinction between paths for clipping and paths for drawing.

Also, I've a clearer opinion on yesterday's changes to the Picture type. The Picture type changed from having attributes stored on both nodes and leaves to having attributes only on leaves. For generating PostScript it is better to have only nodes attributed then the number of gsave ... grestore blocks in the output can be minimized. However node attribution seems unnatural for construction, and I've decided that I prefer easy construction and 'not so good' PostScript. So yesterdays changes are satisfactory - at some point I could do a tree transformation to optimize the PostScript but I don't see that as a priority.

A few of the demos don't work any more, as I'm due to improve the path and picture constructors.