The city of Edinburgh, Scotland’s capital, really comes into its own twice a year. Firstly is August, when its streets are thronged with revelers and amateur PR types (“four stars in the Scotsman!”) promoting their wares at the world-famous performing arts festival. And then the second comes at the end of the year, during the New Year’s Eve period of Hogmanay, which sees anyone claiming long-distant Scots ancestry taking part in the revels for a day or two, just as it seems anyone in Boston on St.