Few performers are so synonymous with Las Vegas as Wayne Newton. And say what you will about the aging icon, but few have as much staying power. Now, Mr. Newton has extended his Sin City residency all the way to June of next year. He was just a teenager when he began singing, and he was a headliner in Las Vegas by 1963, playing at the Flamingo. Since then, he has never left the Strip. His old-school style of nostalgia has held up well over the years, and today he’s still going strong. Now, Wayne Newton has extend his shows…