Merge branch 'mpi_periodic' into 'master'

Mpi periodic

See merge request jschoeberl/netgen!93

libsrc/meshing/meshclass.cpp

@@ -44,6 +44,7 @@ namespace netgen
     cd2names.SetSize(0);
 
 #ifdef PARALLEL
+    this->comm = MPI_COMM_WORLD;
     paralleltop = new ParallelMeshTopology (*this);
 #endif
   }

libsrc/meshing/meshclass.hpp

@@ -32,6 +32,11 @@ namespace netgen
     /// point coordinates
     T_POINTS points;
 
+#ifdef PARALLEL
+    // The communicator for this mesh. (more or less dummy for now!)  
+    MPI_Comm comm;
+#endif
+    
     /// line-segments at edges
     Array<Segment, 0, size_t> segments;
     /// surface elements, 2d-inner elements