Left-wing managers of a Paris theatre occupied by hundreds of homeless African migrants are set to abandon the building because of sex-related violence. They say the crisis at the Gaîté Lyrique – one of the French capital’s most historic arts venues – is now ‘so explosive’ that retreat by this Friday is their only option. Some 200 mainly young men moved in last December when the management gave them free tickets to a ‘Refugees Welcome in France’ conference. But when the conference was finished, the migrants, who mostly come from France's former west African colonies, refused to leave the venue....