Regression: Prev commit (af3623e) broke new window animation

Try removing the Navigator.navigating and inPreview checks. In those cases the
clone should be visible.

Without those checks (together with the clone.get_parent check?) dialogs created
during animation is not hidden.

Also note that the unmapped description in af362e was wrong - unmapped is only
true a short period after the window is created.

tiling.js

@@ -2077,11 +2077,9 @@ function showHandler(actor) {
     if (Scratch.isScratchWindow(metaWindow))
         return;
 
-    if (metaWindow.unmapped)
-        return;
-
-    if (metaWindow.clone.visible || ! onActive || Navigator.navigating
-       || inPreview) {
+    if (!onActive
+        || metaWindow.clone.get_parent() && metaWindow.clone.visible
+       ) {
         actor.hide();
         metaWindow.clone.show();
     }