THEY could be the most unlikely couple ever to take up residence at the White House. If John Kerry wins the Democratic nomination and ousts George Bush in the November presidential elections, prepare for fireworks...not from Kerry himself, but from his missus. Teresa Heinz Kerry is set to become the most colourful and controversial First Lady in American history. While the height of excitement for John, the dry, low-key senator from Massachusetts, would seem to be an afternoon at the library, his wife makes a point of wringing every drop of joy out of life. For instance, she's been shadowing...