Add time stamps to chat

[yuxuibbs]

would be helpful to have timestamp added to chat (maybe even as a hover thing? just add a title attribute to the li or span tag for hover, hours/minutes/seconds would be most useful)

since timer flip is currently just a button that counts down and doesn't enforce anything (not to mention #135 ), it would be helpful to have a timestamp for when the timer is flipped and to have context for when messages were sent so that judges can go back and decide if a -1 is warranted for taking too much time to move or write a solution