Fixing a bug where end of game was not being seen one move ahead of time,
because the wrong layersToClear value was being passed to evalWithNextBlock().
qSearchBreadth is being reverted to 24, since the recent change to 32 had
nothing to do with fixing this problem. Also adding a TODO.txt item related to
picking low-hanging fruit related to the situation where a pit/well is cleared
of all cruft, which usually results in a bonus points situation.
