Build script for Puzzles using bob. I've also added a piece of extra

Build script for Puzzles using bob. I've also added a piece of extra
infrastructure to the mkfiles.pl framework for the convenience of
the build script: it generates `wingames.lst', a list of the Windows
binaries which are ship-worthy games as opposed to nullgame or
command-line auxiliary programs.

[originally from svn r7206]