Didn't get an invitation to Friday's big event? Well, don't feel too bad--you're in pretty good company. In a snub that's raised some eyebrows in Britain, neither of the country's two most recent former prime ministers received an invite. Also left out are President Obama and first lady Michelle Obama. There's no place for either Tony Blair or Gordon Brown among the 1,900-member congregation, even though the other two living former British leaders, Baroness Margaret Thatcher and Sir John Major, were invited. (Thatcher, 85, has declined, citing her health, but Major will be there.) Adding to the awkwardness, when Prince...