Fix rep-draw detection in drop games

In games like Crazyhouse every move is reversible, as captured pieces
can eventually change sides again, and be dropped back on the board.
So we have to search back a full 100 ply for repetitions, passing captures
and Pawn moves.
Implement insufficient mating material for Knightmate

KBK is draw with Royal Knight. With exo-pieces also KNK and KFK.
Use Ctrl key in AnalyzeMode to exclude entered move
Do not move to forwadMostMove when unpausing AnalyzeMode