Ridley Scott cranks up the barbarism in ‘Gladiator II’; Bill Nighy and James Norton star as IVF pioneers in ‘Joy’; jazz is the ‘Soundtrack to a Coup d’Etat’ in a history of colonialism in Congo; ‘Christmas Eve in Miller’s Point’ is a charming ensemble comedy-drama; Andrea Arnold’s ‘Bird’ is a moving work of British social realism; ‘No Other Land’ is an Israeli-Palestinian documentary about destruction in the West Bank — reviews by Danny Leigh and Jonathan Romney