Limit duple-check rule to piece types above 7

Limit duple-check rule to piece types above 7

This to allow implementation of normal extinction variants.
The definition of Spartan Chess had to be adapted to maintain the
duple-check rule there, moving the King definition to the end.
The piece ordering was further changed so that the black pieces now
also are ordered low to high, which gives better move ordering in QS,
as Fairy-Max' idea of MVV/LVA orders attacker on piece-type number,
rather than the defined value.