Use global index sets by the dune-parmg module

This MR contains most of the changes of !22 (closed) , with some extra cleanup.

dune/gfe/parallel/globalp1mapper.hh

-#ifndef DUNE_GFE_GLOBALP1MAPPER_HH
-#define DUNE_GFE_GLOBALP1MAPPER_HH
+#ifndef DUNE_GFE_PARALLEL_GLOBALP1MAPPER_HH
+#define DUNE_GFE_PARALLEL_GLOBALP1MAPPER_HH
 
 /** \brief Include standard header files. */
 #include <vector>
@@ -16,8 +16,6 @@
 
 #include <dune/parmg/parallel/dofmap.hh>
 #include <dune/parmg/parallel/globaldofindex.hh>
-#include <dune/parmg/parallel/redistributematrix.hh>
-#include <dune/parmg/parallel/redistributevector.hh>
 #include <dune/parmg/parallel/datahandle.hh>
 
 namespace Dune {
@@ -91,4 +89,4 @@ namespace Dune {
   };
 
 }
-#endif /* DUNE_GFE_GLOBALP1MAPPER_HH */
+#endif /* DUNE_GFE_PARALLEL_GLOBALP1MAPPER_HH */