Written by DCist contributor E.K. Eckert The lights are just coming up in the main room at Nation Night Club, despite the sun having risen an hour earlier, and Scott Henry is spinning his final record, a remix of Donna Summer’s “Last Dance.” People all around us are crying. Lots of people, and lots of tears. This is, honestly and not in the cliché sense, the end of an era. Before Nation is to be…