[Gui] DAGView: remove few includes

mainly the headers are just sorted

src/Gui/DAGView/DAGRectItem.cpp

@@ -22,14 +22,15 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-#include <QPainter>
 #include <QApplication>
+#include <QPainter>
 #endif
 
 #include <QStyleOptionViewItem>
 
 #include "DAGRectItem.h"
 
+
 using namespace Gui;
 using namespace DAG;