Added support for the parallel solvers of dune-istl.

To support this the solveSystem methods of the LinearSolverInterface gets
an optional additional template parameter of type boost::any. It can hold any
copy constructable object. In our case it is used to pass the information about
the parallelization into the solvers of dune-istl without the compiler needing to know
their type. Inside of LinearSolverIstl::solveSystem we check whether the type stored inside of
boost::any is the new ParallelIstlInformation. If this is the case we extract the information
and use the parallel solvers if available, otherwise we solve serial/sequential.

The new ParallelIstlInformation is needed as the OwnerOverlapCopyCommunication is not copy
constructable. This is indeed a design flaw that should and will fixed upstream, but for the
time being we need ParallelIstlInformation to transfer the ParallelIndexSet and RemoteIndices
objects.

opm/core/linalg/LinearSolverInterface.hpp

@@ -20,6 +20,7 @@
 #ifndef OPM_LINEARSOLVERINTERFACE_HEADER_INCLUDED
 #define OPM_LINEARSOLVERINTERFACE_HEADER_INCLUDED
 
+#include<boost/any.hpp>
 
 struct CSRMatrix;
 
@@ -69,7 +70,8 @@ namespace Opm
                                          const int* ja,
                                          const double* sa,
                                          const double* rhs,
-                                         double* solution) const = 0;
+                                         double* solution,
+                                         const boost::any& add=boost::any()) const = 0;
 
         /// Set tolerance for the linear solver.
         /// \param[in] tol         tolerance value