#2351 Stop flooding master with messages.  Block and only post data when master is ready for it.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18410 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2351 Fix deadlock in VTK writing caused by VTK never picking up messages about faces.  New timings are **very** healthy.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18411 b5f69653-2bf5-0310-8201-b0dafb8e1405
#2351 Fix build.  (Should have re-compiled after adding timing documentation in r18411).

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18412 b5f69653-2bf5-0310-8201-b0dafb8e1405
#1660 Get abstract HDF5 converter to examine which datasets are available.

git-svn-id: https://chaste.cs.ox.ac.uk/svn/chaste/trunk@18413 b5f69653-2bf5-0310-8201-b0dafb8e1405