Not every PBS member station will be repeating its two-part Beatles special from December tonight in prime time – but many will, so it’s certainly worth a heads up, just in case. First comes a new documentary about the making, and the impact, of Magical Mystery Tour, the psychedelic British TV special from 1967 that included such songs as “Fool on the Hill” and “I Am the Walrus.” This documentary, even for hard-core Beatles fans, is chock full of new insights,