issue 14: use Integer.valueOf in delta comparison

Author: dnaumenko

src/difflib/DeltaComparator.java

@@ -7,13 +7,13 @@
  * @author mksenzov
  */
 public class DeltaComparator implements Comparator<Delta>, Serializable {
-
+    private static final long serialVersionUID = 1L;
     public static final Comparator<Delta> INSTANCE = new DeltaComparator();
 
     private DeltaComparator() {
     }
 
     public int compare(final Delta a, final Delta b) {
-        return new Integer(a.getOriginal().getPosition()).compareTo(b.getOriginal().getPosition());
+        return Integer.valueOf(a.getOriginal().getPosition()).compareTo(b.getOriginal().getPosition());
     }
 }