Add missing move when unshadowing and missing XY when deleting.

demos/maxBlocks/index.html

@@ -85,7 +85,7 @@
          maxBlocks: 5,
          toolbox: document.getElementById('toolbox')});
 
-    function onchange() {
+    function onchange(event) {
       document.getElementById('capacity').innerHTML =
           workspace.remainingCapacity();
     }