- supports redistributePar -decompose -fileHandler collated
- supports redistributePar -reconstruct
- does not support redistributePar with collated in redistribution mode

- added contact resistance to turbulentTemperatureCoupledBaffleMixed
- added basic multi-world to turbulentTemperatureRadCoupledMixed
- added unit-testcase to $FOAM_APP/test/multiWorld

- noticed by Robin Knowles with `decomposePar -fields -copyZero`

  The internals for the Foam:cp method combine the behaviour of
  a regular `cp` and `cp -R` combined.

  When source and target are both directories, the old implementation
  created a subdirectory for the contents.
  This normally fine,

      ok:  cp "path1/0/" to "path2/1" -> "path2/1/2"
      BUT: cp "path1/0/" to "path2/0" -> "path2/0/0" !!

  Now add check for the basenames first.
  If they are identical, we probably meant to copy directory contents
  only, without the additional subdir layer.

BUG: decomposePar -fields -copyZero copies the wrong directory

- was using the current time name (usually latest) instead of copying
  the 0 directory

ENH: accept 0.orig directories as a fallback to copy if the 0 directory
is missing

- simplfies differences for OSX

- use orte-info to determine prefix/libdir for openmpi.
  This removes a run-time dependency on mpicc, which is actually
  only needed for building with MPI (not running with MPI).
  The corresponding openmpi devel package (deb/rpm) will not
  necessarily be installed on a particular system.

- retain mpicc logic if the new logic using orte-info does not
  deliver an answer. Final fallback to using 'orterun' to
  infer prefix/libdir.

- Additional logic for intel and msmpi to make it easier to
  locate these vendor packages within ThirdParty
  (ie, under ThirdParty/opt/...)

CONFIG: improve robustness

- add check for absolute path when adding PATH/LD_LIBRARY_PATH etc.

- prefix more variables with '_foam*' to prevent accidental overwrite
  of userspace shell variables when sourcing

- avoid deprecated autoPtr check

- bundle bool values in fvPatchField for compacter allocation

- change useImplicit to a set method taking an argument instead of
  allowing direct access.

ENH: adjust fileName component method

- the location \c npos returns the last component

BUG: incorrect addressing in rcEdge, but not used in the code.

- top-level faceCells() on the boundary list simplifies the creation
  of lduAddressing etc, can also be useful on its own

STYLE: replace isA/refCast combination with a single isA

BUG: 2021-1: Various bug fixes and developments

See merge request !489

ENH: add xrange option

- writeCellData() and writePointData() for polyWriter
- writeProcIDs for generic vtk patch writer

- adjust zone addressing after surface face swap and upon construction

- slices on output and misses file/line information for IOerror

Not tested; from visual inspection

add point snapping to iso-surface topo algorithm (#2210)

See merge request !488

- helps avoid the creation of small face cuts (near corners, edges)
  that result in zero-size faces on output.

CONFIG: make default iso-surface topo regularisation less aggressive

- The full (diagcell) regularisation no longer includes cleaning of
  non-manifold surfaces by removing open edges.
  This can be selected by the 'clean' regularisation option instead.
  ie, 'clean' = 'full' + erode open edges

ENH: additional debug modes for iso-surface topo

- with (debug & 8) dumps out a VTK file of the tets to be cut and the
  calculated open edges.

- PstreamBuffers for parallel VTK output.
  - avoids MPI overflows for larger meshes

- new vtk::lineWriter for writing edges

- vtk::fileWriter::writeUniform now also supports processor-specific
  uniform values instead of assuming that they are identical everywhere.

- support simple mesh subsetting to vtu formats to enable debug output
  for a subsection of an existing polyMesh

- rudimentary support for VTK from cellShapes is intended for handling
  basic primitive cell shapes without a full blown polyMesh description.

  For example,

     // Create an empty polyMesh with points only
     polyMesh debugMesh
     (
         io,
         std::move(points),
         faceList(),     // faces
         labelList(),    // owner
         labelList(),    // neighbour
         true            // syncPar
     );

    // Establish the appropriate VTK sizing for the TET shapes
    vtk::vtuCells vtuCells;
    vtuCells.resetShapes(debugCutTets);
    vtuCells.nPoints(debugMesh.nPoints());

  NOTE
  Since the vtk::internalMeshWriter only uses the polyMesh reference
  for the points, it is also possible to create the vtuCells
  description without a pointField (or from a different mesh
  description) and write out the connectivity using the pointField
  from a different mesh.

STYLE: replace short-circuit Allrun script with Alltest