0.12.0 to 0.13.0:
* More Haddock documenting.
* @lowerLeftUpperRight@ removed from "Wumpus.Core.BoundingBox".
* Added range checking and Ord obligation t to the @bbox@
\'smart\' constructor.
* Numeric instances for "Wumpus.Core.Colour" improved.
* MatrixMult type class simplified
* Dash Pattern made a list of on-off pairs rather than just a
list
* The modules - Wumpus.Core.PictureInternal, Wumpus.Core.PostScript,
Wumpus.Core.SVG & Wumpus.Core.Utils - are no longer exposed.
* Various operators in "Wumpus.Core.PictureLanguage" changed.
* Wumpus.Core.TextEncoding split into an internal and a public
module (internal - Wumpus.Core.TextEncodingInternal, public -
Wumpus.Core.TextEncoder).