Betrayal at Krondor: hash update

No Wine update, as there's currently no 1.6.x version of DOSBox support.
Avadon The Black Fortress: hash update, Wine 1.6.2

1.6.2 may be fixing some bugs with GOG installer? (#3735)
Book of Unwritten Tales: hash update, Wine 1.6.2

1.6.2 may be fixing some bugs with GOG installer? (#3735)