Added Dimensions.ZERO.

src/main/java/pythagoras/d/Dimensions.java

@@ -9,6 +9,9 @@ package pythagoras.d;
  */
 public class Dimensions
 {
+    /** A dimension width zero width and height. */
+    public static final IDimension ZERO = new Dimension(0, 0);
+
     /**
      * Returns a string describing the supplied dimension, of the form <code>widthxheight</code>.
      */

src/main/java/pythagoras/f/Dimensions.java

@@ -9,6 +9,9 @@ package pythagoras.f;
  */
 public class Dimensions
 {
+    /** A dimension width zero width and height. */
+    public static final IDimension ZERO = new Dimension(0, 0);
+
     /**
      * Returns a string describing the supplied dimension, of the form <code>widthxheight</code>.
      */