Board setup mode

[PenguinF]

• [ ] Piece tool window
• [ ] Research H-M interaction for removing pieces from the board
• [ ] Keyboard support similar to regular chess boards
• [ ] Hotkeys for placing/removing pieces; also for changing colors or maybe a cycle hotkey
• [ ] Place pieces by clicking on a piece tool, and then on a square
• [ ] Place pieces by dragging pieces from the tool window to a square
• [ ] Non-modal window or control displaying current errors;
• [ ] Undo, redo stack; plus undo-redo stack tool window (not much unlike Paint.NET)
• [ ] "Begin game" button to make it a regular playing board
• [ ] Action: Set up new position
• [ ] Action: Copy existing position to set-up board (if no moves are made, consider removing the regular game, to serve as an inverse to "Begin game" action)
• [ ] Use a different color set (greyscale?) and other visual cues to distinguish set-up boards from actual playing boards