Leading zeros for time display.

Time is now shown with leading zeros.

7:9 is now 07:09
10:5 is now 10:05
Should change this to:
```lua
    gt.hours = string.format("%02d", (new / 60):floor())
    gt.minutes = string.format("%02d", new % 60)
```

But honestly, you should probably make this toggleable via settings. The game itself does not use leading zeroes, so some people might be confused by this.