split viewport for Qt and VtkViewer

src/Vtk/CMakeLists.txt

@@ -3,6 +3,7 @@ set(HEADERS uLibVtkInterface.h
             vtkContainerBox.h
             vtkHandlerWidget.h
             vtkQViewport.h
+            vtkViewport.h
             vtkPolydata.h
             )
 
@@ -11,6 +12,7 @@ set(SOURCES uLibVtkInterface.cxx
             vtkContainerBox.cpp
             vtkHandlerWidget.cpp
             vtkQViewport.cpp
+            vtkViewport.cpp
             vtkPolydata.cpp
             )