Imagine you could talk with Diane Ravitch for 10 to 15 minutes everyday.  That’s kind of what reading her new book, “The Wisdom and the Witt of Diane Ravitch”, is like.  You’ve probably heard of Ravitch before.   She’s the kindly grandmother you see on the news who used to think standardized tests and school privatization were the way to go but actually had the courage to pull an about face.   She’s that rare thing in public policy –…