The long-unprofitable Chicago Sun-Times, which sold just over four years ago for $1, has been reborn as a nonprofit newspaper with $61 million in backing through a potentially groundbreaking merger with public radio station WBEZ-FM 91.5. The deal, which closed Monday, puts the daily tabloid and its colorful history under the banner of Chicago Public Media, the parent company of WBEZ, forming a nonprofit news organization that reshapes the local media landscape. Chicago Public Media raised $61 million in philanthropic support to finance the merger, with the money pledged over five years to fund…