etc/config.sh/CGAL: updated

Patch contributed by Bruno Santos:
 - "etc/config.sh/CGAL":
   - Indented the contents of the recently added if block.
   - Added comment about using system versions.
   - Library paths are now only added if the respective version is not "boost-system" and "cgal-system".

 - "src/renumber/Allwmake":
   It now relies on the previous file to get the version for
   Boost (the same way as in "makeCGAL"). This is so that it will also
   build "SloanRenumber" if "boost_version" is set to "boost-system".

 - "applications/utilities/mesh/generation/Allwmake":
   It now also relies on the script "config.sh/CGAL" to get the
   version for CGAL. If "cgal_version" is set to "cgal-system", it
   will now also build "foamy*Mesh" utilities and respective
   libraries.

Resolves report http://www.openfoam.org/mantisbt/view.php?id=1232

applications/utilities/mesh/generation/Allwmake

@@ -1,5 +1,11 @@
 #!/bin/sh
 cd ${0%/*} || exit 1    # Run from this directory
+
+# Get CGAL and boost versions
+. $WM_PROJECT_DIR/etc/config.sh/functions
+_foamEval SOURCE_CGAL_VERSIONS_ONLY=yes \
+          $($WM_PROJECT_DIR/bin/foamEtcFile config.sh/CGAL)
+
 set -x
 
 wmake -all blockMesh
@@ -7,7 +13,7 @@ wmake -all extrude
 wmake -all extrude2DMesh
 wmake -all snappyHexMesh
 
-if [ -n "$CGAL_ARCH_PATH" ]
+if [ -n "$CGAL_ARCH_PATH" -o "$cgal_version" = "cgal-system" ]
 then
     foamyMesh/Allwmake
 fi