make some Qt5 specific changes for session management

src/Gui/GuiApplication.cpp

@@ -62,8 +62,14 @@ using namespace Gui;
 GUIApplication::GUIApplication(int & argc, char ** argv)
     : GUIApplicationNativeEventAware(argc, argv)
 {
+#if QT_VERSION > 0x050000
+    // In Qt 4.x 'commitData' is a virtual method
     connect(this, SIGNAL(commitDataRequest(QSessionManager &)),
-            SLOT(slotCommitData(QSessionManager &)), Qt::DirectConnection);
+            SLOT(commitData(QSessionManager &)), Qt::DirectConnection);
+#endif
+#if QT_VERSION >= 0x050600
+    setFallbackSessionManagementEnabled(false);
+#endif
 }
 
 GUIApplication::~GUIApplication()
@@ -132,7 +138,7 @@ bool GUIApplication::notify (QObject * receiver, QEvent * event)
     return true;
 }
 
-void GUIApplication::slotCommitData(QSessionManager &manager)
+void GUIApplication::commitData(QSessionManager &manager)
 {
     if (manager.allowsInteraction()) {
         if (!Gui::getMainWindow()->close()) {

src/Gui/GuiApplication.h

@@ -54,7 +54,7 @@ public:
     boost::shared_ptr<Base::SystemExitException> caughtException;
 
 public Q_SLOTS:
-    void slotCommitData(QSessionManager &manager);
+    void commitData(QSessionManager &manager);
 
 protected:
     bool event(QEvent * event);