Segment popups sometimes wrong about trail info availability

[danavery]

In determining whether to make a trail name line in the trail segment hover popup clickable, the code checks to make sure that trail name appears in the trail metadata.

It should, but doesn't yet, check to see if that trail name is listed in a trailhead somewhere. So the situation sometimes arises where a trail name is in the segment data and the trail data, but not in the trailhead data, and it still gets made clickable. It shouldn't be. We need a check for the trailname in the trailhead data as well.