wumpus-drawing

Copperbox revision 2291.

I've updated Text so it works with the changes to PosObject. DocText is now so direct that it hardly merits building syntax - I'll have to think of some features to add to justify building syntax rather than using the PosObject combinators. Not using PosObject directly does mean that it's harder to create documents with bizarre formatting, though that's a bit of a meek reason to favour the status quo.