wumpus-core

Copperbox revision 2239.

I've devalued the affine transformations in Wumpus-Core - that is, I've given the existing classes longer, more cumbersome names in the expectation that higher-level software will define its own affine operations and want the good names - scale, rotate, translate etc.

Because Wumpus-Core is oblivious to context for contextual units, its makeshift unit handling via the class PsDouble was actually counter-productive (making things more complicated). So I've removed the Unit module where PsDouble was defined as part of this work.