This case also reveals the following bugs:
1) SMESH_MesherHelper::IsReversedSubMesh() incorrectly works on
a coarsely meshed disk
2) Addition of NETGEN-1D2D3D removes already computed faces of a
sub-mesh on a group of FACEs (SMESH_subMesh::cleanDependsOn())
3) Volumes are shown, instead of faces, when displaying a sub-mesh on
a SOLID with only a 2D algo assigned to the sub-mesh (SMESH_subMesh_i.cxx)
