OSLO (Reuters) - Everyone in Norway became a theoretical crown millionaire on Wednesday in a milestone for the world's biggest sovereign wealth fund that has ballooned thanks to high oil and gas prices. Set up in 1990, the fund owns around 1 percent of the world's stocks, as well as bonds and real estate from London to Boston, making the Nordic nation an exception when others are struggling under a mountain of debts. A preliminary counter on the website of the central bank, which manages the fund, rose to 5.11 trillion crowns ($828.66 billion), fractionally more than a million times...