Fix gcc build failure

src/Gui/Flag.cpp

@@ -25,6 +25,7 @@
 #ifndef _PreComp_
 # include <QMenu>
 # include <QMouseEvent>
+# include <Inventor/nodes/SoCamera.h>
 #endif
 #include <Inventor/SbVec2s.h>
 #include "View3DInventorViewer.h"

src/Gui/ManualAlignment.cpp

@@ -32,6 +32,7 @@
 # include <QSplitter>
 # include <QStatusBar>
 # include <QTimer>
+# include <QVBoxLayout>
 # include <Inventor/SoPickedPoint.h>
 # include <Inventor/actions/SoSearchAction.h>
 # include <Inventor/events/SoMouseButtonEvent.h>

src/Gui/ManualAlignment.h

@@ -24,6 +24,7 @@
 #ifndef GUI_MANUALALIGNMENT_H
 #define GUI_MANUALALIGNMENT_H
 
+#include <QPointer>
 #include <Base/Placement.h>
 #include <Base/Vector3D.h>
 #include <Gui/Application.h>

src/Gui/SoFCSelection.cpp

@@ -25,6 +25,7 @@
 #ifndef _PreComp_
 # include <qstatusbar.h>
 # include <qstring.h>
+# include <QGLWidget>
 # include <Inventor/details/SoFaceDetail.h>
 # include <Inventor/details/SoLineDetail.h>
 #endif

src/Gui/View3DInventorViewer.cpp

@@ -73,6 +73,7 @@
 # include <Inventor/SoPickedPoint.h>
 # include <Inventor/VRMLnodes/SoVRMLGroup.h>
 # include <QEventLoop>
+# include <QGLFramebufferObject>
 # include <QKeyEvent>
 # include <QWheelEvent>
 # include <QMessageBox>