As a 20-something in 1975, I remember watching the first “Saturday Night Live” show and thinking how different it was from anything else on television. The gifted, unruly cast members – the Not Ready For Prime Time Players – had a counterculture vibe that hit home for many of us. They seemed to be saying and doing things – about pop culture, dating culture, politics, whatever – that the more staid TV comedy variety and talk shows avoided. I wondered who was behind it all. The creator and longtime producer of the show, Lorne Michaels, is now the subject of “Lorne,” a new documentary directed by Morgan Neville, and, at age 81, it’s the first time he’s opened up for the cameras. Although that “opening up” has to be qualified. The film purports to get behind the facade of the famously enigmatic TV legend. But the face behind the facade turns out to be another facade. Neville had unprecedented, if grudging, on-camera access to Michaels and his creative process, though Michaels’ family was off-limits.…