ENH: improve handling of ThirdParty packages

- 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.

etc/config.sh/functions

@@ -56,7 +56,7 @@ then
         [ -n "$1" ] && export LD_LIBRARY_PATH=$1:$LD_LIBRARY_PATH
     }
 
-    # Prefix to LD_LIBRARY_PATH with additional checking
+    # Prepend to LD_LIBRARY_PATH with additional checking
     # $1 = base directory for 'lib' or 'lib64'
     # $2 = fallback libname ('lib' or 'lib64')
     #
@@ -69,7 +69,7 @@ then
     # Return 0 on success
     _foamAddLibAuto()
     {
-        # Note ksh doesn't have 'local' thus these ugly variable names
+        # Note ksh does not have 'local' thus these ugly variable names
         foamVar_prefix="$1"
         foamVar_end="${1##*-}"
 
@@ -112,6 +112,27 @@ then
     }
 
 
+    # Special treatment for Darwin
+    # - DYLD_LIBRARY_PATH instead of LD_LIBRARY_PATH
+    if [ "$(uname -s 2>/dev/null)" = Darwin ]
+    then
+        unset -f _foamAddLib _foamAddLibAuto 2>/dev/null
+
+        # Prepend DYLD_LIBRARY_PATH
+        _foamAddLib()
+        {
+            [ -n "$1" ] && export DYLD_LIBRARY_PATH=$1:$DYLD_LIBRARY_PATH
+        }
+
+        # Prepend to DYLD_LIBRARY_PATH with additional checking
+        # - use lib-dir script instead of rewriting
+        _foamAddLibAuto()
+        {
+            eval "$($WM_PROJECT_DIR/bin/tools/lib-dir -sh $@)";
+        }
+    fi
+
+
     # Source an etc file, possibly with some verbosity
     # - use eval to avoid intermediate variables (ksh doesn't have 'local')
     if [ "$FOAM_VERBOSE" -a "$PS1" ]

etc/config.sh/mpi

@@ -307,7 +307,7 @@ esac
 
 
 # Add (non-dummy) MPI implementation
-# - dummy MPI already added to LD_LIBRARY_PATH and has no external libraries
+# - dummy MPI already in lib-path and has no external libraries
 if [ "$FOAM_MPI" != dummy ] && type _foamAddLib > /dev/null 2>&1
 then
     if [ -n "$FOAM_EXT_LIBBIN" ]    # External libraries (allowed to be unset)

etc/config.sh/settings

@@ -100,6 +100,13 @@ Linux)
 Darwin)     # Presumably x86_64
     : ${WM_ARCH_OPTION:=64}; export WM_ARCH_OPTION  # Default to 64-bit
     WM_ARCH=darwin64
+    /bin/cat << INCOMPLETE 1>&2
+===============================================================================
+Operating system '$WM_ARCH' has incomplete support in this OpenFOAM release.
+For further assistance, please contact www.OpenFOAM.com
+===============================================================================
+INCOMPLETE
+    echo "Darwin support ($WM_ARCH) is incomplete" 1>&2
     ;;
 
 SunOS)
@@ -112,12 +119,12 @@ SunOS)
     ;;
 
 *)  # An unsupported operating system
-    /bin/cat << UNSUPPORTED_OS 1>&2
+    /bin/cat << UNSUPPORTED 1>&2
 ===============================================================================
-Your '$WM_ARCH' operating system is unsupported by this OpenFOAM release.
+Operating system '$WM_ARCH' is unsupported by this OpenFOAM release.
 For further assistance, please contact www.OpenFOAM.com
 ===============================================================================
-UNSUPPORTED_OS
+UNSUPPORTED
     ;;
 esac