Use shorter labels; using long labels creates problems on the Macintosh.

(Thanks, Just!)
diff --git a/Doc/lib/libcgi.tex b/Doc/lib/libcgi.tex
index 4b01862..cb0a6fb 100644
--- a/Doc/lib/libcgi.tex
+++ b/Doc/lib/libcgi.tex
@@ -15,7 +15,7 @@
 written in Python.
 
 \subsection{Introduction}
-\nodename{Introduction to the CGI module}
+\nodename{cgi-intro}
 
 A CGI script is invoked by an HTTP server, usually to process user
 input submitted through an HTML \code{<FORM>} or \code{<ISINPUT>} element.