Boho hero: arguably the ultimate Doctor, Tom Baker portrayed the legendary Gallifreyan adventurer for seven years and seasons (1974-81), here posing with Daleks outside the iconic BBC Television Centre For many, Blighty in the '70s was a decade, well, to forget. Three-day-weeks, streets-strewn-with-rubbish-causing strikes, crap jalopies, and, of course, the rise of Margaret Thatcher 'Milk…