LONDON (Reuters) - World stocks scaled record highs on Friday and oil prices stayed buoyant in a holiday-shortened week, as optimism grew that a U.S.-China trade deal would soon be signed.Traders returned from their Christmas and Boxing Day break to digest comments from Beijing that it was in close contact with Washington about an initial trade agreement. Earlier, U.S. President Donald Trump had talked up a signing ceremony for the recently struck phase-one trade deal.Rising to another record..