Improve and simplify the use of versions

sources/editor/elementscene.cpp

@@ -35,6 +35,7 @@
 #include "graphicspart/parttext.h"
 #include "ui/qetelementeditor.h"
 #include "ui/elementpropertieseditorwidget.h"
+#include "../qetversion.h"
 
 #include <QKeyEvent>
 #include <algorithm>
@@ -448,7 +449,7 @@ const QDomDocument ElementScene::toXml(bool all_parts)
 	root.setAttribute("hotspot_y",   QString("%1").arg(
 				  -(qRound(size.y() - (ymargin/2)))));
 
-	root.setAttribute("version", QET::version);
+    QetVersion::toXmlAttribute(root);
 	root.setAttribute("link_type", m_element_data.typeToString(m_element_data.m_type));
 
 	//Uuid used to compare two elements