By Tim Ghianni NASHVILLE Tenn. (Reuters) - Singer Miranda Lambert won four Country Music Association Awards on Wednesday, and Luke Bryan took home the top honor as entertainer of the year as U.S. politics and the absence of Taylor Swift played supporting roles in the televised ceremony. Lambert, 30, who led all nominees with nine nods, earned her record fifth female vocalist of the year award. "I don't know what to say. I can't believe I'm standing here. I can't believe this is my life," an emotional Lambert said accepting the award she has won five consecutive years. ...