Allow user to view previous move positions

[jordiedh]

• Clicking on a move shows the position after that move
• Should save current position and allow it to be brought back (with a button or clicking latest move)
• Should be able to flick through position with arrow keys
• Should highlight move made when loading old position (no need for both white and black highlighted)
• Current position should fix highlighting
• Possibly a play from this position button?