message: Add documentation to L2FaceRestriction.
diff: @@ -135,19 +135,19 @@ class L2FaceRestriction : public Operator
  {
  protected:
  const FiniteElementSpace &fes;
  - const int nf;
  - const int ne;
  - const int vdim;
  + const int nf; // Number of faces of the requested type
  + const int ne; // Number of elements
  + const int vdim; // vdim
  const bool byvdim;
  - const int ndofs;
  - const int dof;
  - const int elemDofs;
  + const int ndofs; // Total number of dofs
  + const int dof; // Number of dofs on each face
  + const int elemDofs; // Number of dofs in each element
  const L2FaceValues m;
  - const int nfdofs;
  - Array<int> scatter_indices1;
  - Array<int> scatter_indices2;
  - Array<int> offsets;
  - Array<int> gather_indices;
  + const int nfdofs; // Total number of dofs on the faces
  + Array<int> scatter_indices1; // Scattering indices for element 1 on each face
  + Array<int> scatter_indices2; // Scattering indices for element 2 on each face
  + Array<int> offsets; // offsets for the gathering indices of each dof
  + Array<int> gather_indices; // gathering indices for each dof
  L2FaceRestriction(const FiniteElementSpace&,
  const FaceType,
  