Latest fix for memory checker

tests/memoryChecks/index.js

@@ -27,7 +27,7 @@ BABYLONDEVTOOLS.Loader.require('../validation/validation.js')
                 }
 
                 runTest(index, function() {
-                    BABYLON.Engine.LastCreatedEngine.dispose();
+                    dispose();
                     needInit = true;
                 });
             }

tests/validation/validation.js

@@ -322,4 +322,12 @@ function init() {
     engine.setDitheringState(false);
 }
 
+function dispose() {
+    engine.dispose();
+    currentScene = null;
+    engine = null;
+    document.body.removeChild(canvas);
+    canvas = null;
+}
+
 init();