Adapt WinBoard to Shogi implementation on Variant ICS

Adapt WinBoard to Shogi implementation on Variant ICS

The Variant ICS does not use the '+P' notation for promoted pieces,
neither in the board, nor in SAN, but simply indicates any Gold by 'G',
and uses 'H' and 'D' for +B  and +R. The Shogi promotion code in
LegalityTest() and Disambiguate(), which are used in move Parsing, are
adapted to handle this. Deferred promotions sent to the ICS now use an
== suffix.