wumpus-core

Copperbox revision 1792.

More work on transforming primitives - I've now added instances of the Affine classes for Primitives again.

Previously I saw this as controversial and removed the instances, however now I'm happy that if the code actually works (not properly tested yet), then having instances of these classes is valid, modulo the caveat that the stroke width of lines won't be scaled and possibly other minor distinctions.