OutlineViews: Make behavior consistent with other views

Allow them to be focused, activate also on return/enter. Also fix focus
handling so that assigning a shortcut to "Activate Outline View"
actually
works.

Change-Id: I878777ae0dad493af1715b36ee264a4f0c12443e
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/texteditor/outlinefactory.cpp

@@ -168,6 +168,7 @@ void OutlineWidgetStack::updateCurrentEditor(Core::IEditor *editor)
             newWidget->setCursorSynchronization(m_syncWithEditor);
             addWidget(newWidget);
             setCurrentWidget(newWidget);
+            setFocusProxy(newWidget);
         }
 
         updateFilterMenu();