In Britain they call it Boxing Day . No one knows exactly why it is called like that, but the most plausible theory is that it has to do with holiday gifts, handed over in a “Christmas box”. December 26 is also St. Stephen’s Day, an early  Christian martyr who was stoned to death. In our family, as in many, I expect, it is a sort of “day after”, a day of hangover, when you try to recover from …