This is the main bulk of this boolification work, but although it's
making the largest actual change, it should also be the least
disruptive to anyone interacting with this code base downstream of me,
because it doesn't modify any interface between modules: all the
inter-module APIs were updated one by one in the previous commits.
This just cleans up the code within each individual source file to use
bool in place of int where I think that makes things clearer.

This commit removes the old #defines of TRUE and FALSE from puzzles.h,
and does a mechanical search-and-replace throughout the code to
replace them with the C99 standard lowercase spellings.

patch from Phil Bordelon.)

[originally from svn r8373]

function. Useful in conjunction with the new --save option to
generate lots of games, extract the aux strings from the game
generator, and de-obfuscate them in order to measure statistical
properties of their solutions.

[originally from svn r8352]