The spiritual home of Mars Inc is Slough, an unprepossessing town somewhere under the flight path to London’s Heathrow Airport. It is not a place that sweet dreams are made of. It serves as the British backdrop for Ricky Gervais’s “The Office”. It is also the place where Forrest Mars, in the Depression of the 1930s, came up with two business ideas and a management philosophy that are still quietly shaping the world today.