some cleanups when chasing unappropriate stdout output. Daniel

* debugXML.c tree.c xmlIO.c xmlmemory.c: some cleanups when chasing
  unappropriate stdout output.
Daniel
diff --git a/xmlIO.c b/xmlIO.c
index 929cee0..7fd101c 100644
--- a/xmlIO.c
+++ b/xmlIO.c
@@ -399,6 +399,8 @@
 	return(0);
     if (fil == stdout)
 	return(0);
+    if (fil == stderr)
+	return(0);
     return ( ( fclose((FILE *) context) == EOF ) ? -1 : 0 );
 }