- had occasional remnant use of FOAM_SRC

- useful for builds that don't use the ThirdParty directory at all

- they don't use scotch/metis anyhow, which are the only things
  placed in FOAM_EXT_LIBBIN

- just check WM_PROJECT_DIR instead.

- provide a fallback value when FOAM_EXT_LIBBIN might actually be needed.

Only strictly need FOAM_EXT_LIBBIN for scotch/metis decomposition, and
when these are actually supplied by ThirdParty.
All other ThirdParty dependencies are referenced by BOOST_ARCH_PATH etc.

Can therefore drop the FOAM_EXT_LIBBIN dependency for VTK-related
things, which do not use scotch/metis anyhow.

- has different locations on different systems
  (eg, /usr/bin/lsof or /sbin/lsof)

- this implies that jobControl is a user-resource for OpenFOAM.
  It was previously located under $WM_PROJECT_INST_DIR/jobControl,
  but few users will have write access there.

- an unset FOAM_JOB_DIR variable is treated as "~/.OpenFOAM/jobControl",
  which can partially reduce environment clutter.

- provide argList::noJobInfo() to conveniently suppress job-info on an
  individual basis for short-running utilities (eg, foamListTimes) to
  avoid unneeded clutter.

- previously used the value of $WM_PROJECT, but this is potentially
  inconsistent with what Foam::etcFiles uses.

- ensure proper and sensible handling of empty names.
  Eg, isDir(""), isFile("") are no-ops, and avoid file-stat

- rmDir:
  * optional 'silent' option to suppress messages.
  * removes all possible sub-entries, instead of just giving up on
    the first problem encountered.

- reduced code duplication in etcFiles

ENH: provide WM_USER_RESOURCE_DIRNAME define (in foamVersion.H)

- this is still a hard-coded value, but at least centrally available

- minor bug: 'wclean empty' may have had issues with logical vs physical path

- permit SYSTEMMPI user adjustments via
      etc/config.{csh,sh}/mpi-system
  This can be a convenient place for setting up SYSTEMMPI for OpenFOAM
  without adjusting bashrc, prefs.sh ...

- add a USERMPI type. This represents any generic mpi implementation.
  The user is responsible for supplying an appropriate
  wmake/rules/General/mplibUSERMPI file and managing all settings.

  This type of setup can be useful in combination with specific build
  systems (SPACK, EASYBUILD, etc) or module systems for which the MPI
  variant is part of the installed configuration.

- lazier evaluation of project name and version based on the directory
  name. Avoids heuristics based on directory names unless really needed.

- cope with alternative directory locations.
  For example, OpenFOAM+VERSION etc.

The combination of the two above appears to be sufficient to open up
the directory naming possibilities.

- additional -list-test option (tests for existence of directory).

- cleanup variables last in etc/bashrc for a clean exit code

- this allows the sys-admin to provide base values independent of any
  WM_PROJECT_SITE value.

- support names like openfoam-<VERSION> (eg, what spack uses).
- robustness improvements

- this corresponds to what various module or build systems provide.
  ThirdParty builds are unaffected since they install into FOAM_EXT_LIBBIN

- this makes it possible to perform additional operations
  on surface values that have been previously sampled.

- support vectorField for weighting operations.

- reduce overhead by avoiding creation of weight fields, Sf fields
  and combined surface geometries unless they are actually required.

- extend some similar concepts and operations to volFieldValue

- makes it easier to identify at a later stage

- handle sourcing bashrc with a relative path (issue #383)
- handle sourcing from bash and zsh.
  Still need manual intervention when sourcing dash, sh, or ksh.
- replace grep in etc/cshrc with sed only
- logical instead of physical path for WM_PROJECT_DIR (issue #431).
  Doesn't seem to be possible for csh/tcsh.

  * Continue using physical locations when comparing directories,
    but not for the top-level FOAM_INST_DIR, WM_PROJECT_DIR.

- relocate WM_CC, WM_CXX overrides from etc/config.*/compiler
  to etc/config.*/settings to ensure that they are left untouched
  when etc/config.sh/compiler is sourced while making third-party
  packages (eg, gcc, llvm, CGAL).

- provide fallback FOAM_TUTORIALS setting in RunFunctions

STYLE: remove "~OpenFOAM" fallback as being too rare, non-obvious

- ignore top-level /build and /platforms directories

- minor cleanup of wmake sources

ENH: Function objects - updated logic to determine whether or not to instantiate a time-based function object.  Fixes #439