- streamlined code somewhat, minor attempt to reclaim some memory
 - now use "mesh parts" for patches/zones/sets/etc throughout to avoid
   ambiguity with mesh regions
 - collect superCells and addPointCellLabels in a class. The old version
   actually seemed to have overwritten the addPointCellLabels with each
   cellSet/cellZone. This means that part of the pointFields would be trashed
   in the combination of polyhedral cells, cellSets/cellZones and internalMesh
 - polyDecomp information for muitiple mesh regions, but not yet exploited
 - pointFields now working for cellZones/cellSets
 - extroplating fields onto walls also works as expected for interpolated
   pointFields
 - added tooltips to reader GUI

TODO:
 - pointFields (real and interpolated) for faceSets/faceZones

  - various GUI properties are now animateable="0"
    (meaning they no longer show up on the time-line)
  - move reader switches to the bottom of the GUI
  - move Lagrangian fields above pointFields for better visibility
  - basic support for multiple clouds
  - filter fields based on selection before looping over all the geometry bits
  - mesh conversion functions now return VTK mesh types for easier handling
  - faceZones mesh conversion had points/faces allocation reversed
  - updateInfo with every call to setTime() that changes the timeIndex
    This seems to be the only way to notice Lagrangian fields
  - restore displaying patchnames that got forgotten in the last commit
  - misc reorganization

  - normal mesh data on port0
  - Lagrangian data on port1
  - no fixed block numbers for dividing internalMesh, patches, zones etc.
    This helps avoid ugly gaps in the multiblock output
  - avoid segfault if Lagrangian fields are converted without positions

  TODO:
  - can we label the output ports?
  - the selection of Lagrangian data and fields is wonky.

  - added printMemory() method to aid debugging memory used
  - call UpdateInformation() if the mesh has changed
  - automatic activation of "internalMesh", "p", "U"
    is suppressed if a fvMesh is cached. Otherwise,
    appearing/disappearing volFields can cause a crash

  Note:
  The message "had to make up a selection value" that sometimes occurs
  seems to be paraview related (see paraview mailing list),