automatic scale adjust in BoardPainter::resizeEvent()
(board is always scaled and centered in window)
fixed 'null Pixmap' thing.
(Happened by iterating over all piece types, while WasBiy/InvalidPiece was never Pixmapped)
removed more unused stuff from chessX' BoardView and added move indicators to BoardPainter
changed positioning function for move indicators
(They now will orient on squares 1,60,11 and 17 (depending on flipped state).
 So squares can be displaced as needed. But! I tried to add the ditch by offsetting all squares away from the
middle by a little fraction, but that looks a bit nasty when certain squares are updated(drawn) and their
anti-alias pixels overwrite each other. This problem does not occure when all squares are at uniform integer positions.)
removed BoardView::showMoveIndicator() (it always shows)
implemented 'all reachable squares' hilight