As any Twilighter knows, vampires sparkle in the sunlight as though they have diamonds embedded in their skin. "Twight" author Stephenie Meyer's vampires do at least. That's the one big regret "New Moon" actor Edi Gathegi, who plays Laurent, has as his character bids farewell to the series. I'm not going to spoil it for those who haven't read the book, but suffice to say that Laurent isn't in a…