Make headercheck happy

[[Imported from SVN: r6435]]

dune/solvers/common/permutationmanager.hh

 #ifndef DUNE_PERMUTATIONMANAGER_HH
 #define DUNE_PERMUTATIONMANAGER_HH
 
+#include <algorithm>
 #include <vector>
 
+#include <dune/common/fvector.hh>
 #include <dune/grid/common/exceptions.hh>
 
 //! This file contains the permutation manager class.

dune/solvers/iterationsteps/lineariterationstep.hh

@@ -4,6 +4,7 @@
 #include <vector>
 
 #include <dune/common/bitsetvector.hh>
+#include <dune/common/shared_ptr.hh>
 
 #include "iterationstep.hh"
 

dune/solvers/operators/nulloperator.hh

 #ifndef NULLOPERATOR_HH
 #define NULLOPERATOR_HH
 
+#include <cstddef>
+
 /** \brief Represents the null operator in the needed space
  *
  */

dune/solvers/operators/sumoperator.hh

 #ifndef SUMOPERATOR_HH
 #define SUMOPERATOR_HH
 
+#include <cstddef>
+
 /** \brief represents the sum of two linear operators
  *
  *  The summands may be of arbitrary type. Their names are for historical illustrative reasons where one is a sparse and the other a filled in lowrank matrix