Merge branch 'feature-chunkingComms' into 'develop'

Pstream: added maxCommsSize setting to do (unstructured) parallel transfers in blocks.

Tested:
- with maxCommsSize 0 produces exactly same result as plus.develop
- compiles with label64
- with maxCommsSize e.g. 3 produces exactly same result as plus.develop
- with maxCommsSize=0 exactly the same messages (with Pstream::debug = 1) as plus.develop

See merge request !85

applications/utilities/mesh/advanced/combinePatchFaces/combinePatchFaces.C

@@ -48,7 +48,6 @@ Description
 
 \*---------------------------------------------------------------------------*/
 
-#include "PstreamReduceOps.H"
 #include "argList.H"
 #include "Time.H"
 #include "polyTopoChange.H"
@@ -62,6 +61,7 @@ Description
 #include "motionSmoother.H"
 #include "topoSet.H"
 #include "processorMeshes.H"
+#include "PstreamReduceOps.H"
 
 using namespace Foam;