Added vol/mass weighted averages.

Change-Id: Icd3555ac0d37bbdc295dd2b8931ac5a717a4a03a
Merge topic 'expand_fragment_integration' into next

69177751 Added vol/mass weighted averages.
Update VTK

Change-Id: Ie7b32c0ba8895eaf9c6f57d9be9095cd5ece48c1
Merge topic 'update-vtk-20140310' into next

3ebc3601 Update VTK