Rename IPlugin::shutdown --> IPlugin::aboutToShutdown

Discussed-with: hjk

src/plugins/help/helpplugin.cpp

@@ -358,7 +358,7 @@ void HelpPlugin::extensionsInitialized()
     connect(engine, SIGNAL(setupFinished()), this, SLOT(updateFilterComboBox()));
 }
 
-void HelpPlugin::shutdown()
+void HelpPlugin::aboutToShutdown()
 {
     if (m_sideBar)
         m_sideBar->saveSettings(m_core->settings(), QLatin1String("HelpSideBar"));

src/plugins/help/helpplugin.h

@@ -71,7 +71,7 @@ public:
 
     bool initialize(const QStringList &arguments, QString *error_message);
     void extensionsInitialized();
-    void shutdown();
+    void aboutToShutdown();
 
 private slots:
     void modeChanged(Core::IMode *mode);