added ISABELLE_SCALA, ISABELLE_JAVA;

--- a/etc/settings	Fri Aug 15 23:31:37 2008 +0200
+++ b/etc/settings	Sat Aug 16 13:31:55 2008 +0200
@@ -72,6 +72,9 @@
 ### JVM components (Scala or Java)
 ###
 
+ISABELLE_SCALA="scala"
+ISABELLE_JAVA="java"
+
 classpath "$ISABELLE_HOME/lib/classes/Pure.jar"