Chess game update - functionality

I added a game clock (10 mins for now) and the take back move button. These are just functionality changes not anything major. it took a while because I also had to figure out how to make the clocks go around after the board was flipped so it was taking a long time for that. Also the game now has to read the move list and revert changes to the board for the move back so that also took long. I need to fix some issues with the clock, something I am working on now.