By Kevin Sweeney Defensive improvements and an unwavering belief in coach Hubert Davis turned this season from a disaster into a special one. It finally clicked for North Carolina. A team that spent much of the season being derided as a disappointment in Hubert Davis’s first year as head coach is off to the Final Four, ringing the midnight bell on Saint Peter’s Cinderella run in a game that was never particularly close Sunday. It was a complete and comprehensive beating by the Heels–efficient on offense, organized on defense and unfazed by staring down the darling of March. And it all sets the…