-reverted setValue: removed isReadOnly as parameter.

  -- Allows for more flexability when slider is updated.  The caller 
  can do something based on change event and utilize isReadonly within
their change handler.

src/main/java/com/googlecode/mgwt/ui/client/widget/input/slider/Slider.java

@@ -160,7 +160,7 @@ public Integer getValue() {
 
   @Override
   public void setValue(Integer value) {
-    setValue(value, isReadOnly());
+    setValue(value, true);
   }
 
   @Override