This reverts commit 0ee1ed63.

Feature memory streams

See merge request OpenFOAM-plus!191

- simplify structure.
- protect against nullptr when resetting memory streams
- make UIListStream swappable
- add uiliststream as an example of using a plain std::istream

- as per readInt32(), readInt64() etc.
  Previously only had readScalar() in a two-parameter form.

- these were previously taken from region-local directories
  (eg, constant/region/triSurface), but this becomes difficult to
  manage when there are many files and regions.

- The central InfoSwitch "writeLagrangianPositions" allows writing an
  additional Lagrangian "positions" file, but these were not being
  written by reconstructPar. These are now also written in reconstructPar
  if the central writeLagrangianPositions InfoSwitch is enabled.

NOTES

- "positions" are reconstructed from the processors "coordinates" file

- decomposePar will not attempt to create or redistribute any
  "positions" files

- define regExp::results_type using SubStrings container for handling
  groups. This makes a later shift to std::smatch easier, but changes
  the regExp API for matching with groups. Previously had list element
  0 for regex group 1, now list element 0 is the entire match and list
  element 1 is regex group 1.

  Old:
      List<std::string> mat;
      if (re.match(text, mat))  Info<< "group 1: " << mat[0] << nl;

  New:
      regExp::results_type mat;
      if (re.match(text, mat))  Info<< "group 1: " << mat.str(1) << nl;

- problems were introduced by the change ee252307 (issue #686).
  Affected reading of OBJ files.

  The fallback zone (used to catch unnamed groups/zones), which was
  previously filtered away when not needed. Now handle more explicitly.

ENH: use stringOps::split and low-level read{Label,Scalar} for parsing OBJ file

- also handle stray semi-colons in foamCleanPath.
  Treat like a ':' separator.
  They are incorrect and potentially problematic for shell evals.

improve handling of gmp/mpfr configuration

See merge request OpenFOAM-plus!190

- can tag the version compatibility with a negative number to suppress
  the warnings but retain some information about which version was
  supported.

Simplify argList methods names and add more compat options

See merge request OpenFOAM-plus!188

- export library path for gmp/mpfr from CGAL config files.
  This is required when non-system gmp/mpfr libraries are being
  used, but not using a ThirdParty compiler installation.

- automatically handle lib/ vs lib64/ (eg, for central installations)
  for packages such as boost, CGAL, etc. While the ThirdParty
  compilation of these will normally land in lib64/, this may not be
  the case when they are supplied by another means.

- reworked the handling of foamEtcFile and foamCleanPath for less
  clutter in the configuration files.
  Added the bin/tools/lib-dir script to handle logic that is
  too complex to easily manage in csh.

- previously part of POSIX.C

- for tutorials that are known to run poorly, can provide a
  placeholder Allrun-optional instead of the usual Allrun script.
  If this is detected, the case will be skipped.

- can now be used as previously intended, since the scalarRange
  parsing has been fixed.

- can be used to handle when options become redundant, but it is
  undesirable to treat its presence as an error. Can now tag it as
  being ignored.

     argList::ignoreOptionCompat({"oldOption", 1706}, true);
     argList::ignoreOptionCompat({"oldBoolOpttion", 1706}, false);

     command  -oldOption xyz -oldBoolOpttion

- use succincter method names that more closely resemble dictionary
  and HashTable method names. This improves method name consistency
  between classes and also requires less typing effort:

    args.found(optName)        vs.  args.optionFound(optName)
    args.readIfPresent(..)     vs.  args.optionReadIfPresent(..)
    ...
    args.opt<scalar>(optName)  vs.  args.optionRead<scalar>(optName)
    args.read<scalar>(index)   vs.  args.argRead<scalar>(index)

- the older method names forms have been retained for code compatibility,
  but are now deprecated

- direct parsing of -funcs to ITstream.
- use direct lookup when the option is a word/string