ENH: mpi: use per-application communicator.

...ties/parallelProcessing/redistributePar/redistributePar.C

src/OpenFOAM/db/IOstreams/Pstreams/UPstream.C

src/OpenFOAM/db/IOstreams/Pstreams/UPstream.H

src/OpenFOAM/global/argList/argList.C

src/OpenFOAM/meshes/polyMesh/globalMeshData/globalIndexI.H

src/OpenFOAM/meshes/polyMesh/globalMeshData/globalMeshData.C

...meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.C

...meshes/polyMesh/mapPolyMesh/mapDistribute/mapDistribute.H

...es/polyMesh/mapPolyMesh/mapDistribute/mapDistributeBase.C

...es/polyMesh/mapPolyMesh/mapDistribute/mapDistributeBase.H

...sh/mapPolyMesh/mapDistribute/mapDistributeBaseTemplates.C

src/Pstream/mpi/UPstream.C

...urbulentTemperatureCoupledBaffleMixedFvPatchScalarField.C

...urbulentTemperatureCoupledBaffleMixedFvPatchScalarField.H

src/finiteVolume/Make/files

...PatchFields/derived/mappedField/mappedFieldFvPatchField.C

...ppedMixedFieldFvPatchField/mappedMixedFieldFvPatchField.C

...ppedMixedFieldFvPatchField/mappedMixedFieldFvPatchField.H

...pedMixedFieldFvPatchField/mappedMixedFieldFvPatchFields.C

...pedMixedFieldFvPatchField/mappedMixedFieldFvPatchFields.H