This fix addresses a more general problem than issue #16. Before this fix, multiple renderings of star widgets for the same score do not work. All the container divs of those star widgets end up with the same HTML id so only the first div gets rendered properly.
With this fix, I introduced a creation counter to BaseWidget and used that counter to ensure HTML ids are unique.
The usecase that brought this to my attention involves 1 readonly star widget to display a score and 1 star widget in a modal form for voting purpose.