It's been a long time since Alicia Silverstone was "Clueless." Since then she's earned accolades on screen and stage, most recently in Donald Marguilies's Time Stands Still, directed by Tony Award winner Daniel Sullivan, which she'll take to Broadway in January. At the same time, the longtime environmental activist's unique brand of non-judgmental yet no-holds-barred diet advice was earning a different kind of approval, as she recently told in this interview [excerpted from EcoStilletto ]. Th