Design mode/Qt Designer: Clean up the widget part of it.

- Remove shared subwindow reparenting from EditorWidget, make EditorWidget
  inherit FancyMainWindow. and use just once instance of it instead of
  per-editor ones.
- Embedded FormEditorStack into EditorWidget as a centralwidget.
- Changed FormWindowEditor's base class from IEditor to SharedTools::FormWindowHost
  (Widget) to be embedded into FormEditorStack (no need to be an IEditor),
  Remove Designer::Internal::FormWindowHost which had little functionality.
- Add Design Mode widget to FormEditorW which has FakeToolBar and EditorWidget
  (single instance) in a vertical layout.
- Removed ProxyAction class handling dock view toggle actions of several EditorWidgets
  (no longer necessary since there is just once instance). Moved "View menu" to bottom.
- Started to make FakeToolBar work as a single instance listening on changing
  xml editors
- Include-file/slot connection clean-up.

src/plugins/designer/formeditorstack.h

@@ -34,6 +34,11 @@
 #include <QtCore/QList>
 #include <QtCore/QString>
 
+QT_BEGIN_NAMESPACE
+class QDesignerFormWindowInterface;
+class QDesignerFormEditorInterface;
+QT_END_NAMESPACE
+
 namespace Core {
     class IEditor;
 }
@@ -54,34 +59,35 @@ class FormEditorStack : public QStackedWidget
     Q_OBJECT
     Q_DISABLE_COPY(FormEditorStack);
 public:
-    FormEditorStack();
-    ~FormEditorStack();
+    explicit FormEditorStack(QWidget *parent = 0);
+
     Designer::FormWindowEditor *createFormWindowEditor(DesignerXmlEditorEditable *xmlEditor);
     bool removeFormWindowEditor(Core::IEditor *xmlEditor);
     bool setVisibleEditor(Core::IEditor *xmlEditor);
-    Designer::FormWindowEditor *formWindowEditorForXmlEditor(Core::IEditor *xmlEditor);
+    Designer::FormWindowEditor *formWindowEditorForXmlEditor(const Core::IEditor *xmlEditor) const;
+    Designer::FormWindowEditor *formWindowEditorForFormWindow(const QDesignerFormWindowInterface *fw) const;
+    FormWindowEditor *activeFormWindow() const;
 
 private slots:
     void formChanged();
     void reloadDocument();
+    void updateFormWindowSelectionHandles();
 
 private:
+    inline int indexOf(const QDesignerFormWindowInterface *) const;
+    inline int indexOf(const Core::IEditor *xmlEditor) const;
+
     void setFormEditorData(Designer::FormWindowEditor *formEditor, const QString &contents);
-
-    struct FormXmlData;
-    QList<FormXmlData*> m_formEditors;
-
-    FormXmlData *activeEditor;
-
     struct FormXmlData {
+        FormXmlData();
         DesignerXmlEditorEditable *xmlEditor;
         Designer::FormWindowEditor *formEditor;
-        int widgetIndex;
     };
-
+    QList<FormXmlData> m_formEditors;
+    QDesignerFormEditorInterface *m_designerCore;
 };
 
-}
-}
+} // namespace Internal
+} // namespace Designer
 
 #endif // FORMEDITORSTACK_H