Add obsolescence note to the module descriptions that get added to the
list of module synopses at the front of the chapter; based on a comment
from Aahz <aahz@panix.com>.
diff --git a/Doc/lib/libregsub.tex b/Doc/lib/libregsub.tex
index ed7c119..b41b700 100644
--- a/Doc/lib/libregsub.tex
+++ b/Doc/lib/libregsub.tex
@@ -3,7 +3,7 @@
 
 \declaremodule{standard}{regsub}
 \modulesynopsis{Substitution and splitting operations that use
-                regular expressions.}
+                regular expressions.  \strong{Obsolete!}}
 
 
 This module defines a number of functions useful for working with