[Gui] So headers: remove unused includes

- also sort out some headers to be used in precompiled headers
- also move a boost header to precompiled headers

src/Gui/View3DInventorViewer.cpp

@@ -20,8 +20,8 @@
  *                                                                         *
  ***************************************************************************/
 
-
 #include "PreCompiled.h"
+
 #ifndef _PreComp_
 # include <float.h>
 # ifdef FC_OS_WIN32
@@ -43,6 +43,9 @@
 # include <Inventor/actions/SoHandleEventAction.h>
 # include <Inventor/actions/SoRayPickAction.h>
 # include <Inventor/annex/HardCopy/SoVectorizePSAction.h>
+# include <Inventor/details/SoDetail.h>
+# include <Inventor/elements/SoLightModelElement.h>
+# include <Inventor/elements/SoOverrideElement.h>
 # include <Inventor/elements/SoViewportRegionElement.h>
 # include <Inventor/events/SoEvent.h>
 # include <Inventor/events/SoKeyboardEvent.h>
@@ -73,9 +76,6 @@
 # include <QWheelEvent>
 #endif
 
-# include <Inventor/elements/SoLightModelElement.h>
-# include <Inventor/elements/SoOverrideElement.h>
-
 #include <App/Document.h>
 #include <App/GeoFeatureGroupExtension.h>
 #include <Base/Console.h>