By: Addison Wylie Cruise ships can be vulnerable places, and the audience witnesses that in Stephan Bergmann’s dawdling doc The Last Gigolos.  The viewer boards a ship occupied by an elderly crowd – most are single, all are eager to set sail.  As the cruise moves from one destination to the next, the passengers find chemistry with each other as they discuss ways to stay energetic as well as their sombreness when grieving lost loved ones….