Remove dependency on Board.hs in Client.hs
Remove dependency on Board in Exam.hs
Remove Board.hs and convertion function from/to Board
[Enhancement] Bench.hs shows more detail
[Bugfix] fix bug in AI.hs

AI.hs does not get stuck into an infinite loop
Modify AI.hs

Negascout-like reordering of movements
Create interface to human (Human.hs)