ENH: Added ctkVTKSliceView class used to display the slices of a vtkImageData

The underlying renderWindow can be split as a grid N*M where
 item 1 displays slice Z,
 item 2, slice Z+1
 item 3, slice Z+2
 ...
 item N*M, slice Z+N*M

Setting the renderWindowLayoutType to either LeftRightTopBottom
or LeftRightBottomTop allow to change the order of the grid item.

Libs/Visualization/VTK/Widgets/CMakeLists.txt

@@ -31,6 +31,9 @@ SET(KIT_SRCS
   ctkVTKRenderView.cpp
   ctkVTKRenderView.h
   ctkVTKRenderView_p.h
+  ctkVTKSliceView.cpp
+  ctkVTKSliceView.h
+  ctkVTKSliceView_p.h
   )
 
 # Headers that should run through moc
@@ -39,6 +42,8 @@ SET(KIT_MOC_SRCS
   ctkVTKMatrixWidget.h
   ctkVTKRenderView.h
   ctkVTKRenderView_p.h
+  ctkVTKSliceView.h
+  ctkVTKSliceView_p.h
   )
 
 # UI files