Remove some Qt4 compatibility code

include/Model.h

@@ -41,10 +41,6 @@ public:
 		m_displayName( _display_name ),
 		m_defaultConstructed( _default_constructed )
 	{
-#if QT_VERSION < 0x050000
-		connect( this, SIGNAL( dataChanged() ), this,
-			SLOT( thisDataChanged() ), Qt::DirectConnection );
-#endif
 	}
 
 	virtual ~Model()
@@ -89,19 +85,6 @@ signals:
 	// emitted if properties of the model (e.g. ranges) have changed
 	void propertiesChanged();
 
-#if QT_VERSION < 0x050000
-	// emitted along with dataChanged(), but with this model as an argument
-	// workaround for when QObject::sender() and Qt5 are unavailable
-	void dataChanged( Model * );
-
-private slots:
-	void thisDataChanged()
-	{
-		emit dataChanged( this );
-	}
-
-signals:
-#endif
 } ;