wumpus-core

Copperbox revision 1917.

I've improved the handling of null paths (paths with an empty list of path segments) and empty text labels - labels with empty string for text. Neither generate PostScript and SVG output any more. Previously they generated output that wasn't actually printed (i.e. moveto instructions but no lineto instructions), the improvement saves code size. There is also a new constructor in the Picture API to create empty paths.