Allow promotion on two-leg move

Allow promotion on two-leg move

After a second-leg of a SAN move the parser now checks for apromotion
suffix, and if any is found this is used by ParseOneMove / LoadGameOneMove
to set the promoChar. In converting to SAN for the parseList the promoChar
is now appended to the second leg, rather than the first, and the Edit Book
window will also show it. The promochar is written behind the kill square
in the moveList, and when sending the move there to the engine it is
appended to the second move of the multi-move pair.