Deactivate deprecation of dune-fufem FE-bases

The bases from dune-functions can currently not be used as a drop in
replacement, because the latter do not allow to select the range type
as we did in dune fufem. Before deprecating these, we should either
be sure to a happy with double once and for all, or wait until
dune-functions is fixed and then remove all uses of fufem bases
in fufem itself. Currently the deprecations just clutter the
compiler output and you cannot get rid of this.

dune/fufem/functionspacebases/dgpqkbasis.hh

 #ifndef DG_PQKBASIS_HH
 #define DG_PQKBASIS_HH
 
+/*
 #warning This file is deprecated.  All implementations of function space bases in dune-fufem \
   are in the process of being replaced by counterparts in the new dune-functions module. \
   Those are syntactically different, but semantically very close to the dune-fufem implementations. \
   To get rid of this warning, replace all occurrences of the Q1NodalBasis<...> class in your code \
   by DuneFunctionsBasis<Dune::Functions::LagrangeDGBasis<...> >.
+*/
 
 /**
     \brief Global basis for discontinous Galerkin spaces with local Pk or Qk elements

dune/fufem/functionspacebases/p0basis.hh

 #ifndef P0_BASIS_HH
 #define P0_BASIS_HH
 
+/*
 #warning This file is deprecated.  All implementations of function space bases in dune-fufem \
   are in the process of being replaced by counterparts in the new dune-functions module. \
   Those are syntactically different, but semantically very close to the dune-fufem implementations. \
   To get rid of this warning, replace all occurrences of the P0Basis<...> class in your code \
   by DuneFunctionsBasis<Dune::Functions::PQkNodalBasis<...,0> >.
+*/
 
 /**
    @file

dune/fufem/functionspacebases/p1nodalbasis.hh

 #ifndef P1_NODALBASIS_HH
 #define P1_NODALBASIS_HH
 
+/*
 #warning This file is deprecated.  All implementations of function space bases in dune-fufem \
   are in the process of being replaced by counterparts in the new dune-functions module. \
   Those are syntactically different, but semantically very close to the dune-fufem implementations. \
   To get rid of this warning, replace all occurrences of the P1NodalBasis<...> class in your code \
   by DuneFunctionsBasis<Dune::Functions::PQ1NodalBasis<...> >.
+*/
 
 /**
    @file

dune/fufem/functionspacebases/p2nodalbasis.hh

 #ifndef P2_NODALBASIS_HH
 #define P2_NODALBASIS_HH
 
+/*
 #warning This file is deprecated.  All implementations of function space bases in dune-fufem \
   are in the process of being replaced by counterparts in the new dune-functions module. \
   Those are syntactically different, but semantically very close to the dune-fufem implementations. \
   To get rid of this warning, replace all occurrences of the Q1NodalBasis<...> class in your code \
   by DuneFunctionsBasis<Dune::Functions::PQkNodalBasis<...> >.
+*/
 
 /**
    @file

dune/fufem/functionspacebases/p3nodalbasis.hh

 #ifndef P3_NODALBASIS_HH
 #define P3_NODALBASIS_HH
 
+/*
 #warning This file is deprecated.  All implementations of function space bases in dune-fufem \
   are in the process of being replaced by counterparts in the new dune-functions module. \
   Those are syntactically different, but semantically very close to the dune-fufem implementations. \
   To get rid of this warning, replace all occurrences of the Q1NodalBasis<...> class in your code \
   by DuneFunctionsBasis<Dune::Functions::PQkNodalBasis<...,3> >.
+*/
 
 /**
    @file

dune/fufem/functionspacebases/q1nodalbasis.hh

 #ifndef Q1_NODALBASIS_HH
 #define Q1_NODALBASIS_HH
 
+/*
 #warning This file is deprecated.  All implementations of function space bases in dune-fufem \
   are in the process of being replaced by counterparts in the new dune-functions module. \
   Those are syntactically different, but semantically very close to the dune-fufem implementations. \
   To get rid of this warning, replace all occurrences of the Q1NodalBasis<...> class in your code \
   by DuneFunctionsBasis<Dune::Functions::PQ1NodalBasis<...> >.
-
+*/
 
 /**
    @file