Stopwatch: one line quick fixes

As per @chrismorast's comment on #847, I removed the white fill on the lap/reset buttons.
![screenshot from 2014-07-02 13 29 57](https://cloud.githubusercontent.com/assets/4411471/3459601/853f6350-020e-11e4-8142-956f1441c7a2.png)

I also used `startend` to trigger "stopwatch online", and I fixed a problem where the lap button doesn't reset when you press the reset button while the stopwatch is running.