Detect and work around the following bug:

Detect and work around the following bug:
dnl /* ----------------------------------------------- */
dnl /* Problem 14: Access control. Friendship is not   */
dnl /* granted although explicitly declared.           */
dnl template <int N, int M> class T      {    void bar ();  };
dnl
dnl template <int M>        class T<1,M> {
dnl   private:
dnl     static int i;
dnl     template <int N1, int N2> friend class T;
dnl };
dnl
dnl template <int N,int M> void T<N,M>::bar () {
dnl   T<N-1,M>::i;
dnl };
dnl
dnl template class T<2,1> ;

We work around by making a certain function in the Tensor<1,dim> class public.

git-svn-id: https://svn.dealii.org/trunk@5612 0785d39b-7218-0410-832d-ea1e28bc413d