Christian Ponder isn’t sure whether Percy Harvin will be back

Vikings coach Leslie Frazier said Monday that receiver Percy Harvin will remain with the team in 2013.  Vikings quarterback Christian Ponder has somewhat less optimism. “I’m not sure, I don’t know,” Ponder told Paul Allen of KFAN on Tuesday.  “We’ll see.  I mean, we’ll see how everything shakes out.  I’m not sure what Rick Spielman’s…