wumpus-basic

Copperbox revision 1894.

I've removed the BoundaryAnchors and LRText / LRSymbol modules.

The code from BoundaryAnchors has be put back into the DrawingComposition module. I'm not going to attempt to make code common between drawing composition and text-line alignment and composition, so the boundary anchors need not be in their own module.

LRText didn't work with the changes to Wumpus-Core. As it is due to be superseded by the current work on text handling, I won't be spending time updating it.