- now use findEtcEntry() instead to handle file or directory.

  Added findEtcEntries(), which provides provides a common code basis
  for findEtcDirs(), findEtcFiles() ...

- for some special cases we wish to mark command-line arguments as
  being optional, in order to do our own treatment. For example,
  when an arbitrary number of arguments should be allowed.

  Now tag this situation with argList::noMandatoryArgs().
  The argList::argsMandatory() query can then be used in any further
  logic, including the standard default argument checking.

- with the new default check, can consolidate the special-purpose

      "setRootCaseNonMandatoryArgs.H"

  into the regular

      "setRootCase.H"

- revert to a simple "setRootCase.H" and move all the listing related
  bits to a "setRootCaseLists.H" file. This leaves the information
  available for solvers, or whoever else wishes, without being
  introduced everywhere.

- add include guards and scoping to the listing files and rename to
  something less generic.

     listOptions.H -> setRootCaseListOptions.H
     listOutput.H  -> setRootCaseListOutput.H

- similar to the foamEtcFile script -mode=... option, the specific
  search location (user/group/other) can now also specified for
  string expansions and as a numerical value for etcFile()

  For example, if searching for group or other (project) controlDict,
  but not wishing to see the user controlDict:

    1.  foamEtcFile -mode=go controlDict

    2.  fileName dictFile("<etc:go>/controlDict");
        dictFile.expand();

    3.  etcFile(controlDict, false, 0077);

  The default behaviour for searching all contexts is unchanged.

    1.  foamEtcFile controlDict

    2.  fileName dictFile("<etc>/controlDict");
        dictFile.expand();

    3.  etcFile(controlDict);

- also replaced a few instances of readIfPresent with opt<> for
  constant values.

- regression was introduced by 628b2445

- change previous default (convert all faceZones unless -noFaceZones
  specified) with the default behaviour to only convert face zones on
  request.

- uses the '-faceZones' option as per foamToEnsight

- this allows it to work like readListIfPresent() but with a list as
  the return value, which can be useful for a const context.

- prefer this to using the OPENFOAM define since this improves the
  internal consistency with the build information.

  The API information could change between builds without the
  etcFiles.C being recompiled whereas the value of
  Foam::foamVersion::api is force updated during the build (triggers
  recompilation of globals.Cver)

Reference:
Comte-Bellot, G., and Corrsin, S., "Simple Eulerian Time Correlation of
Full- and Narrow-Band Velocity Signals in Grid-Generated, 'Isotropic'
Turbulence," Journal of Fluid Mechanics, Vol. 48, No. 2, 1971,
pp. 273–337.

- now placed under postProcessing/checkMesh and postProcessing/checkAMI,
  respectively.

  Output files are now also tagged with the id of the patch, in case
  there are multiple AMI patches in use.

- use cellCentres() instead of volField equivalent for vtk conversion

- make looping variables more consistent

- centralize the transcription of OpenFOAM -> vtk tuples

- eg for foamVersion.H

- provide default WM_DIR if not already set, to improve robustness if a
  reduced environment is used

- add etc/ to WM_PROJECT_SITE search. This makes the site directory
  structure consistent with the OpenFOAM structure.
  Eg,

      WM_PROJECT_SITE/etc/..
      WM_PROJECT_SITE/bin/..
      WM_PROJECT_SITE/platforms/..

- Don't set/export WM_OSTYPE.  The default is POSIX and is properly
  defaulted throughout, including in CMakeLists-OpenFOAM.txt (also for
  Catalyst)

- this splits a larger changeset for a gradual implementation

- removed reliance on ParaView_INCLUDE_DIR variable for conveying the
  major.minor version information when compiling. This can be somewhat
  fragile and also adds variable that is an unnecessary when running
  (only used when compiling).

  Instead use `have_pvplugin_support` function in paraviewFunctions
  wmake script to determine the maj.min from the PV_PLUGIN_PATH
  since we have already defined the output path there with paraview
  maj.min numbering.

  Can now build with paraview from the operating system,
  provided that it has develop headers available.

      ParaView_VERSION=system

  In the etc/config.sh/paraview setup, the maj.min is taken from
  the corresponding `paraview --version` output and used when
  defining the PV_PLUGIN_PATH.

  During the build, the include path taken from `paraview-config`
  for a system installation, from the guess installation root
  of the paraview binary, or ParaView_DIR otherwise.

NB: using a system ParaView for building runTimePostProcessing is unsupported.

- these types of builds appear to have various library resolution issues
  (eg, libexpat not being loaded). Additionally, the build logic does
  not yet cover this type of use case.

- improved flexibility

- reconstruction of Lagrangian positions/fields now handled as a class
  for better modularity

- cfindObject() for const pointer access.

- getObject() for mutable non-const pointer access, similar to the
     objectRegistry::getObjectPtr()

- cfindObject(), findObject(), getObject() with template type access
  to also check the headerClassName.

  For example,

      cfindObject("U")  ->  good
      cfindObject<volVectorField>("U") -> good
      cfindObject<volScalarField>("U") -> nullptr

  This allows inversion of looping logic.

    1) Obtain the names for a particular Type

       for (const word& objName : objs.sortedNames<Type>())
       {
           const IOobject* io = objs[objName];
           ...
       }

    2) Use previously obtained names and apply to a particular Type

       for (const word& objName : someListOfNames)
       {
           const IOobject* io = objs.cfindObject<Type>(objName);
           if (io)
           {
               ...
           }
       }

- foamToEnsight, foamToEnsightParts, profiling

- useful when generating formatted output such as tables.

- add -region option and -fields filtering

- foamToVTK, foamToEnsight, foamToEnsightParts

- can be used, for example, to visualize all wall cells - for quality
  or other purposes - without requiring an intermediate faceSet for
  the selection. Request arising from pending merge !213.

- vtkWrite with moving mesh was not updated the subsets properly,
  which caused it to crash.

- foamToVTK -overwrite ignored for single region cases,
  was working for multi-region cases

- minor documentation changes

- Within strings it is preferable to use the "<etc>" instead.
  Most use cases for the old "~OpenFOAM" expansion have been obsoleted
  by the #includeEtc directive.

- use std::string instead of c-string for the string constants

- centralize some definitions of resources into foamVersion.H

  Now expose some of the hard-coded values used in foamEtcFiles()
  so that they can be known or even overridden as required.

  Relocate to src/OpenFOAM/include as a constant location.

- uses wmake, without OpenFOAM libraries.

  The application and libray serve as a minimal test case for wmake,
  but can also be used to generate a minimal library/executable pair
  target for testing of packaging etc.