DDM spectrum comparison getdp vs smallfem: hum?

git-svn-id: https://geuz.org/svn/gmsh/trunk@19890 59c8cabf-10d6-4a28-b43f-3936b85956c4
DDM vectorial 3D: spectrum with correct basis functions (tet coherent with tri)

git-svn-id: https://geuz.org/svn/gmsh/trunk@19891 59c8cabf-10d6-4a28-b43f-3936b85956c4
git-svn-id: https://geuz.org/svn/gmsh/trunk@19892 59c8cabf-10d6-4a28-b43f-3936b85956c4