0.3.0.0: 20180718
-----------------
* Switch backend to diagrams-rasterific, losing the dependency on Cairo.
* Upgrade to diagrams 1.4.
* Various new puzzle types, including Minesweeper, Tents, Snake,
Country Road, Killer Sudoku.
0.2.0.0: 20161211
-----------------
* Upgrade diagrams version.
* Add various new puzzle types.
* Add solution code markers.
0.1.0.4: 20141115
-----------------
* add installation and usage instructions to README
* merge puzzle-draw-cmdline
* update for diagrams 1.2 and ghc 7.8
* add new puzzle types: Bahnhof, Cave
* rename `countnumbers` to `meanderingnumbers`
* include and use a nicer font
* command-line option to list supported puzzle types
* various tweaks and fixes
0.1.0.3: 20140519
-----------------
* add new puzzle types: Maximal Lengths, Prime Place, Magic Labyrinth
0.1.0.2: 20140419
-----------------
* add new puzzle types: Japanese Sums, Coral
0.1.0.1: 20140409
-----------------
* add new puzzle type: Tapa
0.1.0.0
-------
* first release