If the French-born octogenarian Tomi Ungerer is known at all in the U.S., it’s for the dozens of children’s books he wrote and illustrated, like his series about the Mellop family of pigs, and darker stories such as The Three Robbers and Otto: The Autobiography of a Teddy Bear. The retrospective “All In One” includes copious drawings from his books along with examples of advertising work, political posters addressing racism and war, and, tucked away in a back room, rather mild erotic drawings. Most interesting, however, are Ungerer’s childhood sketchbooks, filled with biting, deftly rendered pictures documenting the Nazi occupation of his hometown of Strasbourg.