changed maintainer-clean dependency with suggestion from Crispin Flowerday

* doc/Makefile.am: changed maintainer-clean dependency with
  suggestion from Crispin Flowerday (bug #157634)
* debugXML.c: fixed crash when ATTRIBUTE or DOCUMENT nodes
  were specified with debugDumpNode (bug #160621)
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 3ca1491..459872e 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -92,7 +92,7 @@
 clean-local:
 	rm -f *~ *.bak *.hierarchy *.signals *-unused.txt
 
-maintainer-clean-local: clean
+maintainer-clean-local: clean-local
 	rm -rf libxml-decl-list.txt libxml-decl.txt 
 
 rebuild: api all