Holdings: “We conclude that the Rosen-Durling test requirements—that (1) the primary reference be “basically the same” as the challenged design claim; and (2) any secondary references be “so related” to the primary reference that features in one would suggest application of those features to the other—are improperly rigid. The statutory rubric along with Supreme Court precedent including Whitman Saddle, Graham, and KSR, all suggest a more flexible approach than the Rosen-Durling test when determining obviousness.”