Report file size of cached packages.

install_and_cache_pkgs.sh

@@ -62,7 +62,7 @@ for package in ${normalized_packages}; do
           if test -f $f; then echo "${f:1}"; fi;  #${f:1} removes the leading slash that Tar disallows
         done | 
         xargs tar -czf "${cache_filepath}" -C /      
-      echo "done."            
+      echo "done (compressed size $(du -k "${cache_filepath}" | cut -f1))."
     fi
 
     # Comma delimited name:ver pairs in the all packages manifest.