Change MPITestLayer so that only external borders, not borders between processes, are initialized.  The internal borders should be filled by MPI routines.
Change MPITestLayer so that only external borders, not borders between processes, are initialized.  The internal borders should be filled by MPI routines.

git-svn-id: 173bfced7225b0a4144fa0e9d72f2fb8f54e5b79@5223 7c0444ca-5550-0410-9008-faecdbe78eb5

PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,PetaVision/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV,dpaiton/OpenPV