Backup and restore facilities

Added backup and restore facilities for grid and dofvector. Either call

problemStat.backup(adaptInfo);

(This will backup the files to [name]->backup->grid and [name]->backup->solution) and instead of initialize() call the function

problemStat.restore(INIT_ALL);

(This will read the grid and solution from the files [name]->restore->grid and [name]->restore->solution)

Or you can call

problemStat.backup(filename)

and

problemStat.restore(filename) -> std::unique_ptr<Grid>

directly to backup and restore the grid of the problemStat and dofvector.backup(filename) and dofvector.restore(filename) to backup and restore the data of the dofvector.

If the grid does not support backup-restore, the current gridView is written. This means that the hierarchy information is lost. A warning is printed in this case.

src/amdis/ProblemStat.inc.hpp

@@ -6,6 +6,7 @@
 
 #include <dune/common/hybridutilities.hh>
 #include <dune/common/timer.hh>
+#include <dune/grid/common/capabilities.hh>
 #include <dune/typetree/childextraction.hh>
 
 #include <amdis/AdaptInfo.hpp>
@@ -489,23 +490,26 @@ template <class Traits>
 void ProblemStat<Traits>::
 backup(std::string const& filename) const
 {
-  try {
+  if (Dune::Capabilities::hasBackupRestoreFacilities<Grid>::v)
     Dune::BackupRestoreFacility<Grid>::backup(*grid_, filename);
-  } catch (Dune::NotImplemented const&) {
+  else {
     warning("Falling back to backup of gridview.");
     BackupRestoreByGridFactory<Grid>::backup(gridView(), filename);
   }
 }
 
+
 template <class Traits>
 void ProblemStat<Traits>::
 backup(AdaptInfo& adaptInfo)
 {
   auto param = Parameters::get<std::string>(name_ + "->backup->grid");
-  std::string grid_filename = param ? *param : name_ + "_" + std::to_string(adaptInfo.timestepNumber()) + ".grid";
+  std::string grid_filename = param ? *param :
+    name_ + "_" + std::to_string(adaptInfo.timestepNumber()) + ".grid";
 
   auto param2 = Parameters::get<std::string>(name_ + "->backup->solution");
-  std::string solution_filename = param2 ? *param2 : name_ + "_" + std::to_string(adaptInfo.timestepNumber()) + ".solution";
+  std::string solution_filename = param2 ? *param2 :
+    name_ + "_" + std::to_string(adaptInfo.timestepNumber()) + ".solution";
 
   backup(grid_filename);
   solution_->backup(solution_filename);
@@ -519,14 +523,14 @@ restore(std::string const& filename)
 {
   // restore grid from file
   std::unique_ptr<Grid> grid;
-  try {
+  if (Dune::Capabilities::hasBackupRestoreFacilities<Grid>::v)
     grid.reset(Dune::BackupRestoreFacility<Grid>::restore(filename));
-  } catch (Dune::NotImplemented const&) {
+  else
     grid.reset(BackupRestoreByGridFactory<Grid>::restore(filename));
-  }
   return std::move(grid);
 }
 
+
 template <class Traits>
 void ProblemStat<Traits>::
 restore(Flag initFlag)