Goodbye, Kendra Spears. Hello, Princess Salwa Aga Khan.The 25-year-old American model married Prince Rahim Aga Khan, son of the spiritual leader of the world’s Shia Ismaili Muslim denomination, in Geneva, Switzerland over the weekend.Spears grew up in Seattle and got a degree in sociology from the University of Washington. In 2008, she entered a modeling contest organized by the Ford model manag