New section header style.
Fix up a few synopses.
diff --git a/Doc/lib/libsys.tex b/Doc/lib/libsys.tex
index 1f37bc8..eadd978 100644
--- a/Doc/lib/libsys.tex
+++ b/Doc/lib/libsys.tex
@@ -1,7 +1,8 @@
-\section{Built-in Module \module{sys}}
+\section{\module{sys} ---
+ System-specific parameters and functions.}
\declaremodule{builtin}{sys}
-\modulesynopsis{Access system specific parameters and functions.}
+\modulesynopsis{Access system-specific parameters and functions.}
This module provides access to some variables used or maintained by the
interpreter and to functions that interact strongly with the interpreter.