update changes.html

Installation/changes.html

@@ -108,6 +108,16 @@ and <code>src/</code> directories).
 
 <HR>
 
+<h3>Spatial Sorting</h3>
+<ul>
+      <li>Add the possibility to sort points on a sphere along
+          a space-filling curve using the functions
+          <code>CGAL::hilbert_sort_on_sphere</code> and
+          <code>CGAL::spatial_sort_on_sphere</code>.</li>
+</ul>
+
+
+
 <h2 id="release4.4">Release 4.4 </h2>
 <div>
   <!-- <p> Release date: October 2013 </p> -->