variables for the "world" MPI communicator. The latter are to be found in
world_comm instead. mp_global should be used only to start and to end the
various parallelization levels. Many small but harmless changes: a few
variables removed or moved to another module in most cases.
git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@10558 c92efa57-630b-4861-b058-cf58834340f0
giannozz