Merge from trunk.

git-svn-id: https://svn.dealii.org/branches/branch_petscscalar_complex@31593 0785d39b-7218-0410-832d-ea1e28bc413d

diff --cc deal.II/source/numerics/data_out.cc
Simple merge

diff --cc deal.II/source/numerics/data_out_faces.cc
Simple merge

diff --cc deal.II/source/numerics/data_out_rotation.cc
Simple merge

diff --cc deal.II/source/numerics/matrix_tools.cc
Simple merge