ENH: direct support for broadcast of bitSet

- the internal data are contiguous so can broadcast size and internals
  directly without an intermediate stream.

ENH: split out broadcast time for profilingPstream information

STYLE: minor Pstream cleanup

- UPstream::commsType_ from protected to private, since it already has
  inlined noexcept getters/setters that should be used.

- don't pass unused/unneed tag into low-level MPI reduction templates.
  Document where tags are not needed

- had Pstream::broadcast instead of UPstream::broadcast in internals

tutorials/incompressible/simpleFoam/motorBike/system/profiling

@@ -0,0 +1,15 @@
+// -*- C++ -*-
+
+profiling
+{
+    type  parProfiling;
+
+    libs  (utilityFunctionObjects);
+
+    // Report stats on exit only (instead of every time step)
+    executeControl  onEnd;
+    writeControl    none;
+}
+
+
+// ************************************************************************* //