added HOLCF/Streams.thy (with concatenation etc.)

--- a/NEWS	Mon Apr 12 12:18:48 2004 +0200
+++ b/NEWS	Mon Apr 12 12:52:08 2004 +0200
@@ -159,6 +159,10 @@
   highly recommended.  See "HOL/Refute.thy" for details.
 
 
+*** HOLCF ***
+
+* Streams now come with concatenation and are part of the HOLCF image
+
 New in Isabelle2003 (May 2003)
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