- unused, does not run in parallel

- avoid enclosing namespace in fvMeshSubset

- make the purpose more explicit, and reduces some work for the
  compiler as well.

- make construct from UList explicit and provide corresponding
  assignment operator.

- add construct,insert,set,assignment from FixedList.
  This is convenient when dealing with things like edges or triFaces.

splitMeshRegions: handle flipping of faces for surface fields

subsetMesh: subset dimensionedFields

decomposePar: use run-time selection of decomposition constraints. Used to
    keep cells on particular processors. See the decomposeParDict in

$FOAM_UTILITIES/parallel/decomposePar:
  - preserveBaffles: keep baffle faces on same processor
  - preserveFaceZones: keep faceZones owner and neighbour on same processor
  - preservePatches: keep owner and neighbour on same processor. Note: not
    suitable for cyclicAMI since these are not coupled on the patch level
  - singleProcessorFaceSets: keep complete faceSet on a single processor
  - refinementHistory: keep cells originating from a single cell on the
    same processor.

decomposePar: clean up decomposition of refinement data from snappyHexMesh

reconstructPar: reconstruct refinement data (refineHexMesh, snappyHexMesh)

reconstructParMesh: reconstruct refinement data (refineHexMesh, snappyHexMesh)

redistributePar:
  - corrected mapping surfaceFields
  - adding processor patches in order consistent with decomposePar

argList: check that slaves are running same version as master

fvMeshSubset: move to dynamicMesh library

fvMeshDistribute:
  - support for mapping dimensionedFields
  - corrected mapping of surfaceFields

parallel routines: allow parallel running on single processor

Field: support for
  - distributed mapping
  - mapping with flipping

mapDistribute: support for flipping

AMIInterpolation: avoid constructing localPoints

- redistributePar to have almost (complete) functionality of decomposePar+reconstructPar
- low-level distributed Field mapping
- support for mapping surfaceFields (including flipping faces)
- support for decomposing/reconstructing refinement data

- redistributePar to have almost (complete) functionality of decomposePar+reconstructPar
- low-level distributed Field mapping
- support for mapping surfaceFields (including flipping faces)
- support for decomposing/reconstructing refinement data

This reverts commit c5bea524.

This reverts commit b18f6cc1.

 - operator+=  : add in the listed keys
 - operator-=  : remove the listed keys
 - operator&=  : intersection of keys
 - added xfer constructor (just in case)
 - moved labelHashSet typedef to HashSet.H, for consistency with the
   wordHashSet typedef being there and since it is used so often