Admin/build

--- a/Admin/build	Thu Jun 23 14:52:32 2011 +0200
+++ b/Admin/build	Thu Jun 23 16:10:22 2011 +0200
@@ -84,6 +84,7 @@
 
 function build_jars ()
 {
+  "$ISABELLE_HOME/lib/scripts/java_ext_dirs" >/dev/null
   pushd "$ISABELLE_HOME/src/Pure" >/dev/null
   "$ISABELLE_TOOL" env ./build-jars "$@" || exit $?
   popd >/dev/null