[Bug-gnubg] Aspect ration of board

[Holger]

Hi,

imho the board size should be reverted to its old aspect ratio. It looked 
better, the chequer animation now looks a bit cumbersome and most of all it 
broke a lot of things:

The html image export is broken (sorry for stating some time ago that it 
worked, I only looked whether the files were generated), the sensitive area 
for the dice is not where it should be, the problems with the dynamic board 
numbers, the disappearing chequers in edit mode.

And maybe we could use the space below the board for other useful things.

Regards,

        Holger