By Jan Worth-Nelson Everybody in the lobby of The Whiting auditorium seemed happy Thursday afternoon as jazz great Wynton Marsalis came to town to ring in a new C.S. Mott Foundation partnership with Jazz at Lincoln Center in New York  for kids, music, and after school programs. Joining Marsalis, who arrived in the late afternoon before a free public concert held later,  was a roomful of Flint elementary school students eager to meet the musician and hear some riffs.  They clapped and kept time  as Marsalis explained “improvisation” using “Happy Birthday to You” and cheerfully...