Isabelle manuals now also available as PDF;

--- a/NEWS	Fri May 28 18:20:58 1999 +0200
+++ b/NEWS	Mon May 31 19:08:26 1999 +0200
@@ -33,6 +33,8 @@
 
 *** General ***
 
+* Isabelle manuals now also available as PDF;
+
 * improved browser info generation: better HTML markup (including
 colors), graph views in several sizes; isatool usedir now provides a
 proper interface for user theories (via -P option);