More files for convex_hull

xs/xsp/Geometry.xsp

@@ -0,0 +1,23 @@
+%module{Slic3r::XS};
+
+%{
+#include <myinit.h>
+#include "Geometry.hpp"
+%}
+
+%package{Slic3r::Geometry};
+
+%{
+
+Polygon*
+convex_hull(points)
+    Points      points
+    PREINIT:
+        const char* CLASS = "Slic3r::Polygon";
+    CODE:
+        RETVAL = new Polygon ();
+        convex_hull(points, *RETVAL);
+    OUTPUT:
+        RETVAL
+
+%}