Wrap vtkAtom and vtkBond in Python

Thanks to David Gobbi for the suggestion, and Jean Favre for raising
the issue on our mailing list.

Common/DataModel/CMakeLists.txt

@@ -254,8 +254,6 @@ set_source_files_properties(
 
 set_source_files_properties(
   vtkAMRBox
-  vtkAtom
-  vtkBond
   vtkBoundingBox
   vtkCellType
   vtkDataArrayDispatcher
@@ -279,6 +277,8 @@ set_source_files_properties(
   )
 
 set_source_files_properties(
+  vtkAtom
+  vtkBond
   vtkCellType.h
   vtkBoundingBox.cxx
   vtkColor.h