Stopwatch needs to prepend a 0 to centiseconds lower than 10

[chris-gong]

For example, a time like 1:05 will show up as 1:5. However, a zero does need to be prepended to the five in this case.

[chris-gong]

Adding to this issue that the colon (:) should be replaced with a period (.). Also, the clock should loop once it reaches 99.99 seconds.

[chris-gong]

Fixed the first part of this issue in commit 5f2255b