Use SMCalloutView's rightAccessoryView in Tours.

SMCalloutView has a pretty good approximation of MapKit's callout layout. Might as well take advantage of it.

Reduces the amount of whitespace on right side of Tours callouts.
Make map links from People open in Maps. #540
Merge pull request #544 from MIT-Mobile/3.6/tours-callout-layout

3.6/tours callout layout