New section header style.

Fix up a few synopses.
diff --git a/Doc/lib/libstring.tex b/Doc/lib/libstring.tex
index 226f453..f7189fd 100644
--- a/Doc/lib/libstring.tex
+++ b/Doc/lib/libstring.tex
@@ -1,4 +1,5 @@
-\section{Standard Module \module{string}}
+\section{\module{string} ---
+         Common string operations.}
 \declaremodule{standard}{string}
 
 \modulesynopsis{Common string operations.}