Log: begin part B
Log
TetrisBoard: initialize an active and backup array
Add a private committed boolean
TetrisBoard: Add widths and heights arrays
TetrisBoard: Add maxHeight
TetrisBoard: Reorganize field declaration section
TetrisBoard: Add shadows for all fields except board and committed

(and DEBUG)
Change TetrisBoard constr. param case, because it's bothering me
Implement TetrisBoard width and height accessors
Implement TetrisBoard.getMaxHeight
Implement TetrisBoard.getGrid
Implement undo
Implement commit

All of the heavy lifting will be done by the place method.
Log