[Part] Move ArcEngine into own file in Gui module

src/Gui/SoFCDB.cpp

@@ -74,6 +74,7 @@
 #include "Inventor/SoAutoZoomTranslation.h"
 #include "Inventor/SoDrawingGrid.h"
 #include "propertyeditor/PropertyItem.h"
+#include "ArcEngine.h"
 
 
 using namespace Gui;
@@ -193,6 +194,8 @@ void Gui::SoFCDB::init()
 
     SelectionObject                 ::init();
 
+    ArcEngine                       ::initClass();
+
     qRegisterMetaType<Base::Vector3f>("Base::Vector3f");
     qRegisterMetaType<Base::Vector3d>("Base::Vector3d");
     qRegisterMetaType<Base::Quantity>("Base::Quantity");