Cablevision’s Charles Dolan struck one of the years biggest media deals in May by swallowing whole the entire Newsday behemoth. Rupert Murdoch was the other contender after the Tribune Company announced that it wanted to rid itself of Long Islands big monopoly daily. But Cablevision came up with the sweeter offer: $650 million. At least Murdoch owns other newspapers; this is the first paper owned by the Dolans (Charlie and his son Jim). Will they do right by Newsday, its staff, and its readers? Well, the Knicks were the first basketball team they boughtand look how that turned out.