LPS-45938 Rating ignores decimal places and does not round up/down

Hi Nate,

the displayed number of stars is a bit confusing right now:

After rating something, in ratings.js we are using the upper value of  the average score. So if the average score is e.g. 1.1, two stars is displayed.

However, after refreshing the page it turns back to one star. In ratings/page.jsp we don't care about the decimal places, so if even if the average score is  e.g. 1.9, only one star is displayed.

I think we should round these values. 
However, I added a new attribute, so the behavior can be tuned by using it.

Could you please review my changes?

Thanks,
Tamás