After bans on full-face veils, head scarves in schools and rules about students’ skirt lengths, France’s perennial problem with Muslim women’s attire has taken its most farcical turn yet with a new controversy over the “burkini,” body-covering swimwear whose name is an amalgam of burqa and bikini. As of Thursday, five French mayors had banned the burkini, calling it, variously, a threat to public order, hygiene, water safety and morality, tantamount to a new weapon of war against the French republic. Thierry Migoule, an official with the city of Cannes, the first to ban the burkini, declared the swimwear “clothing that conveys an allegiance to the terrorist movements that are waging war against us.