I'm sick and tired of having unfinished puzzle code lying around on

I'm sick and tired of having unfinished puzzle code lying around on
several different systems in strange directories. So I'm creating an
`unfinished' directory within source control, and centralising all
my half-finished, half-baked or otherwise half-arsed puzzle
implementations into it. Herewith Sokoban (playable but rubbish
generation), Pearl (Masyu - rubbish generation and nothing else),
Path (Number Link - rubbish generation and nothing else) and NumGame
(the Countdown numbers game - currently just a solver and not even a
generator yet).

[originally from svn r6883]