- avoids removal of files and the dummy fallback

- this allows more use of the runTimePostProcessing functionObject
  that will fail more gracefully if the proper version could not be
  built.

  The dummy functionObject simply emits a message that it is not available.

- generalize some of the library extensions (.so vs .dylib).
  Provide as wmake 'sysFunctions'

- added note about unsupported/incomplete system support

- centralize detection of ThirdParty packages into wmake/ subdirectory
  by providing a series of scripts in the spirit of GNU autoconfig.
  For example,

      have_boost, have_readline, have_scotch, ...

  Each of the `have_<package>` scripts will generally provide the
  following type of functions:

      have_<package>          # detection
      no_<package>            # reset
      echo_<package>          # echoing

  and the following type of variables:

      HAVE_<package>          # unset or 'true'
      <package>_ARCH_PATH     # root for <package>
      <package>_INC_DIR       # include directory for <package>
      <package>_LIB_DIR       # library directory for <package>

  This simplifies the calling scripts:

      if have_metis
      then
          wmake metisDecomp
      fi

  As well as reducing clutter in the corresponding Make/options:

      EXE_INC = \
          -I$(METIS_INC_DIR) \
          -I../decompositionMethods/lnInclude

      LIB_LIBS = \
          -L$(METIS_LIB_DIR) -lmetis

  Any additional modifications (platform-specific or for an external build
  system) can now be made centrally.

- sentinel was not working properly when building user-space routines

Eg,
    librunTimePostProcessing.so
    librunTimePostProcessing.so.7 -> librunTimePostProcessing.so.7.1.0
    librunTimePostProcessing.so.7.1.0

- centralize handling of paraview/vtk versioning into wmake/cmakeFunctions

- use "-pvMAJ.MIN" suffix for similarity with the paraview convention

- use sentinel file to ensure clean change of intermediate targets

- ensure all library files are being properly removed

- Could be related to interrupted builds.
  So if there are any parts of the build that rely on an explicit
  'wmakeLnInclude', make sure that the contents are properly updated.

--

ENH: improved feedback from top-level Allwmake

- Report which section (libraries, applications) is being built.

- Provide final summary of date, version, etc, which can be helpful
  for later diagnosis or record keeping.

- The -log=XXX option for Allwmake now accepts a directory name
  and automatically appends an appropriate log name.
  Eg,
      ./Allwmake -log=logs/  ->> logs/log.linux64GccDPInt32Opt

  The default name is built from the value of WM_OPTIONS.

--

BUG: shell not exiting properly in combination with -log option

- the use of 'tee' causes the shell to hang around.
  Added an explicit exit to catch this.

--

- Detecting the '-k' (-non-stop) option at the top-level Allwmake, which
  may improve robustness.

- Explicit continue-on-error for foamyMesh (as optional component)

- unify format of script messages for better readability

COMP: reduce warnings when building Pstream (old-style casts in openmpi)