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

src/OpenFOAM/db/dynamicLibrary/codedBase/codedBase.C

@@ -28,6 +28,7 @@ License
 #include "dynamicCode.H"
 #include "dynamicCodeContext.H"
 #include "dlLibraryTable.H"
+#include "Pstream.H"
 #include "PstreamReduceOps.H"
 #include "OSspecific.H"
 #include "Ostream.H"