Guardian: Any book by the heir to throne which starts “This is a call to revolution” is arresting. Add to that the fact that the title is Harmony, bearing in mind the cacophanous clashes in Prince Charles’s own life, and you might think that you are in for a thriller. You would be wrong. The book, co-written with Tony Juniper, ex-director of Friends of the Earth, and BBC Radio 3 broadcaster Ian Skelly, may be the heaviest ever produced by a member of the royal family, and not just because of …