Merge master into next

* commit 'aa525d5d662ea6c7036e47a07e4c8a146a773e5f':

Change-Id: Ib335b00f79132eb0f9783eee7d385031fd217572
Merge topic 'newest-xdmf' into next

94dea340 expose subsets in xdmf3 reader
fcc3b2f1 bump vtk to get xdmf3 with subsets and functions