set hull from vertex format

The user can create a convex hull from a vertex format, not directly from a list of vertices. That's interesting because in some 3D engines convex hulls are typically created from a render mesh that might structure a vertex in different ways in the memory.

examples/testbed/tests/hull_contact_test.h

@@ -66,7 +66,7 @@ public:
 				points[j] = p;
 			}
 
-			hull->Set(points, count);
+			hull->Set(sizeof(b3Vec3), points, count);
 		}
 
 		{