On fades, only unhighlight if already highlight.

In added services, when you fade a service, it should also toggle
highlights off. The original code would toggle the highlight flag
regardless of whether it actually needed it, which causes problems
downstream in the code.
Merge pull request #656 from kadams54/fix-unhiding-unrelated-service

On fades, only unhighlight if already highlight.

In added services, when you fade a service, it should also toggle
highlights off. The original code would toggle the highlight flag
regardless of whether it actually needed it, which causes problems
downstream in the code.
Reduce machine change event noise.