Domain wall fermions now invert ; have the basis set up for

Tanh/Zolo * (Cayley/PartFrac/ContFrac) * (Mobius/Shamir/Wilson)
Approx        Representation               Kernel.

All are done with space-time taking part in checkerboarding, Ls uncheckerboarded

Have only so far tested the Domain Wall limit of mobius, and at that only checked
that it
i)  Inverts
ii) 5dim DW == Ls copies of 4dim D2
iii) MeeInv Mee == 1
iv) Meo+Mee+Moe+Moo == M unprec.
v) MpcDagMpc is hermitan
vi) Mdag is the adjoint of M between stochastic vectors.

That said, the RB schur solve, RB MpcDagMpc solve, Unprec solve
all converge and the true residual becomes small; so pretty good tests.

lib/communicator/Grid_communicator_base.h

@@ -27,7 +27,7 @@ class CartesianCommunicator {
 #endif
 
     // Constructor
-    CartesianCommunicator(std::vector<int> &pdimensions_in);
+    CartesianCommunicator(const std::vector<int> &pdimensions_in);
 
     // Wraps MPI_Cart routines
     void ShiftedRanks(int dim,int shift,int & source, int & dest);

lib/communicator/Grid_communicator_mpi.cc

@@ -5,7 +5,7 @@ namespace Grid {
 
   // Should error check all MPI calls.
 
-CartesianCommunicator::CartesianCommunicator(std::vector<int> &processors)
+CartesianCommunicator::CartesianCommunicator(const std::vector<int> &processors)
 {
   _ndimension = processors.size();
   std::vector<int> periodic(_ndimension,1);

lib/communicator/Grid_communicator_none.cc

@@ -1,7 +1,7 @@
 #include "Grid.h"
 namespace Grid {
 
-CartesianCommunicator::CartesianCommunicator(std::vector<int> &processors)
+CartesianCommunicator::CartesianCommunicator(const std::vector<int> &processors)
 {
   _processors = processors;
   _ndimension = processors.size();