Fix virginity of pieces in setup position

Fix virginity of pieces in setup position

Only royal and corner pieces got their virginity bits set when they
started on the original location, because these bits were only used
for castling. But this caused problems for the Met move in Cambodian Chess.
There was in fact no reason not to extend this to all pieces.
It might even solve a so far undetected problem in Seirawan.
But in Makruk it isextra important, because WinBoard always considers
that played from a setup position, because of the non-standard Pawn rank.