[Rating] - visibility improvement

[neil-s]

In the basic rating, unfilled stars are so light by default, they are barely visible. The example in the docs perfectly illustrates this, so not creating a separate repro jsfiddle.

Perhaps setting 100% opacity for the star icon, a darker color, or a thicker outline, would make it more usable. Of course, this is not strictly a bug, and easily modifiable in the site theme, but a more accessible default would be great.

[jlukic]

They probably should be filled like star rating