“Her hair is Harlow gold/Her lips sweet surprise.” The choice of “Bette Davis Eyes” for the opening sequence of “Valentino: The Last Emperor” was like the rest of Matt Tyrnauer’s documentary: innately emotive, but never gratuitously. Whether documenting Valentino’s pre-show meltdown or a tête-à-tête with Karl Lagerfeld (during which Lagerfeld confirms that he considers contemporary [...]