ENH: parallel: overhaul of parallel mapping

- 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

applications/utilities/parallelProcessing/decomposePar/decomposeParDict

@@ -17,11 +17,61 @@ FoamFile
 
 numberOfSubdomains  2;
 
+
+// Optional decomposition constraints
+//constraints
+//{
+//    preserveBaffles
+//    {
+//        //- Keep owner and neighbour of baffles on same processor (i.e.
+//        // keep it detectable as a baffle). Baffles are two boundary face
+//        // sharing the same points
+//        type    preserveBaffles;
+//    }
+//    preserveFaceZones
+//    {
+//        //- Keep owner and neighbour on same processor for faces in zones
+//        type    preserveFaceZones;
+//        zones   (".*");
+//    }
+//    preservePatches
+//    {
+//        //- Keep owner and neighbour on same processor for faces in patches
+//        //  (only makes sense for cyclic patches. Not suitable for e.g.
+//        //   cyclicAMI since these are not coupled on the patch level. Use
+//        //   singleProcessorFaceSets for those)
+//        type    preservePatches;
+//        patches (".*");
+//    }
+//    singleProcessorFaceSets
+//    {
+//        //- Keep all of faceSet on a single processor. This puts all cells
+//        //  connected with a point, edge or face on the same processor.
+//        //  (just having face connected cells might not guarantee a balanced
+//        //  decomposition)
+//        // The processor can be -1 (the decompositionMethod chooses the
+//        // processor for a good load balance) or explicitly provided (upsets
+//        // balance)
+//        type    singleProcessorFaceSets;
+//        singleProcessorFaceSets ((f1 -1));
+//    }
+//    refinementHistory
+//    {
+//        //- Decompose cells such that all cell originating from single cell
+//        //  end up on same processor
+//        type    refinementHistory;
+//    }
+//}
+
+
+// Deprecated form of specifying decomposition constraints:
 //- Keep owner and neighbour on same processor for faces in zones:
 // preserveFaceZones (heater solid1 solid3);
 
 //- Keep owner and neighbour on same processor for faces in patches:
-//  (makes sense only for cyclic patches)
+//  (makes sense only for cyclic patches. Not suitable for e.g. cyclicAMI
+//   since these are not coupled on the patch level. Use
+//   singleProcessorFaceSets for those)
 //preservePatches (cyclic_half0 cyclic_half1);
 
 //- Keep all of faceSet on a single processor. This puts all cells
@@ -32,12 +82,13 @@ numberOfSubdomains  2;
 // for a good load balance) or explicitly provided (upsets balance).
 //singleProcessorFaceSets ((f0 -1));
 
-
 //- Keep owner and neighbour of baffles on same processor (i.e. keep it
 //  detectable as a baffle). Baffles are two boundary face sharing the
 //  same points.
 //preserveBaffles true;
 
+
+
 //- Use the volScalarField named here as a weight for each cell in the
 //  decomposition.  For example, use a particle population field to decompose
 //  for a balanced number of particles in a lagrangian simulation.