LOS ANGELES _ Actress Daniele Watts, who appeared in “Django Unchained,” is complaining that she was handcuffed and briefly put in the back of a squad car after a public display of affection with her white companion.Brian Lucas told KCBS-TV in a joint interview with Watts that he suspects police mistook the black actress for a prostitute “because he was asking me questions like, ‘Who is she? How do you know her? Are you together?”