[uzfibwjb] Progressive endgame punctuation

Modify the punctuation in denoting chess endgame moves (usually tablebase endgames) to carry information about progress.  Assuming a winning position, classify moves the attacker makes as progressive (shortens the distance to mate or conversion), regressive (lengthens the distance to mate), or neutral (does not change the distance to mate), or drawing, or losing.

! means the only progressive move, but neutral moves exist.
!! means not only the unique progressive move, but all other moves are regressive or give up at least half a point. No neutral moves exist.
!!! means all other moves give up at least half a point.
!!!! means all other moves lose.

Neutral but "logical" moves are sometimes acceptable so long as the player eventually makes progress.

We can also add:
? means regressive.
?? gives up half a point (drawing a winning position).
??? gives up a full point (losing a winning position).