find which movement are needed and add a movements counter
add test cube to find why rotations don't work
add euristic search structure.
Heuristic: reponse to user answer. Find the ball's cell
Heuristic: iterate on no good mvt to find the best next mvt
remove useless method
remove useless comments
update comment
Heuristic: find cell only from available cells
Heuristic: Display the instruction at the right place
Change attended position description