Partly resolves "Implement state copy in AST"

eraser-base/src/main/jastadd/Item.jrag

@@ -137,7 +137,9 @@ aspect ItemHandling {
   //--- setStateFromBoolean ---
   public abstract void Item.setStateFromBoolean(boolean value);
   public void ColorItem.setStateFromBoolean(boolean value) {
-    setBrightness(value ? 100 : 0);
+    if (getState().getBrightness()==0) {
+      setBrightness(value ? 100 : 0);
+    }
   }
   public void DateTimeItem.setStateFromBoolean(boolean value) {
     // there is no good way here
@@ -389,6 +391,12 @@ aspect ItemHandling {
     getRoot().addRule(createControllerRule(controllerItem,this));
   }
 
+  public void Item.synchronizeWith(Item item) {
+    addControlledBy(item);
+    addControlling(item);
+  }
+
+
   
   private Rule Item.createControllerRule(Item controllerItem, Item controlledItem) {
     Rule rule = new Rule();