Cube Control: step 2.
Rename 'state' to 'screen'
Rename some classes.
The 3x3x3 Solver finished - here the last piece of work, locking the centers of the 3x3x3 cube in place so that RubikStateSolver's color picker cannot change them ( the CUBE3 solver assumes this )
Progress implementing RubikCube.retObjectString()