PHILADELPHIA — Crowds of young and old Marines and Navy members gathered along the riverside to celebrate and to salute service — and to mourn the fallen. And for a chance to peer out into a perfect Philadelphia fall sky as a fleet of the most powerful military ships glided up the Delaware for the city and the world to behold. Hundreds of veterans, active service members, families of the lost, and dignitaries came to Mustin Field at the Navy Yard on Thursday for the opening ceremony of