Show Best Times For Puzzles

[Toonwoons]

I've been getting really good at some of these puzzles, and I think it would be a fun feature to show your fastest time completing each difficulty in each game.

Not everyone will care about their best time, so it should be an on/off toggle in the settings. My idea is to start a hidden (or shown) timer on game generation, and record the fastest time in the drop-down box for difficulty, like in the screenshot. Alternatively, it could go in the corner.

[chrisboyle]

I just noticed we already have #324 for this so let's track it there.