Rename debug.h to debugtools.h.

diff --git a/documentation/debugging.sgml b/documentation/debugging.sgml
index 5cc0131..5868bcc 100644
--- a/documentation/debugging.sgml
+++ b/documentation/debugging.sgml
@@ -209,7 +209,7 @@
           channel <literal>xxx</literal>, do:
         </para>
         <programlisting>
-#include "debug.h"
+#include "debugtools.h"
 
 ....
 
@@ -219,7 +219,7 @@
           Some examples from the code:
         </para>
         <programlisting>
-#include "debug.h"
+#include "debugtools.h"
 
 ...
 
@@ -500,7 +500,7 @@
           Thus, to use it, do something on the following lines:
         </para>
         <programlisting>
-#include "debug.h"
+#include "debugtools.h"
 
 ...