mv package from experimental to trunk

will replace currently undocumented stuff in NT package

Arithmetic_kernel/test/Arithmetic_kernel/Arithmetic_kernel.cpp

@@ -0,0 +1,18 @@
+#include <iostream>
+#include <CGAL/basic.h>
+#include <CGAL/Arithmetic_kernel.h>
+
+#if defined(CGAL_HAVE_DEFAULT_ARITHMETIC_KERNEL)
+
+#include <CGAL/Test/_test_arithmetic_kernel.h>
+
+int main() {
+
+  typedef CGAL::Arithmetic_kernel AK;
+  CGAL::test_arithmetic_kernel<AK>();
+  return 0;
+}
+
+#else
+int main() { return 0; }
+#endif