By Lisa Iesse Writer HAMILTON / SIX NATIONS OF THE GRAND – Shelley Niro’s “500 Year Itch” exhibit comes in like a “velvet hammer” to open the Art Gallery of Hamilton’s (AGH) winter exhibition. Shelley Falconer, AGH director, remembers the first time she came across Niro’s work, “it was like a gut-wrench,” she tells the crowd. It’s opening day, Saturday February 24, at the AGH, hundreds of people overflow from the gallery’s halls for the special retrospective of Niro’s work, which also includes new works by the internationally acclaimed artist and filmmaker. “The way you could tap into female archetypes with this bemused radiant intelligence, it hit me and it stayed with me,” Falconer told Niro and the gathering. Falconer quotes a friend who once said aptly, “Shelley’s work is…