preparing release of libxml2-2.6.27 fix a small problem with preproc flags

* NEWS configure.in testapi.c doc//*: preparing release of
  libxml2-2.6.27
* include/libxml/tree.h: fix a small problem with preproc flags
Daniel
diff --git a/doc/APIchunk23.html b/doc/APIchunk23.html
index c635968..effe8f5 100644
--- a/doc/APIchunk23.html
+++ b/doc/APIchunk23.html
@@ -353,6 +353,7 @@
 <a href="html/libxml-tree.html#xmlBufferShrink">xmlBufferShrink</a><br />
 <a href="html/libxml-catalog.html#xmlCatalogRemove">xmlCatalogRemove</a><br />
 <a href="html/libxml-parserInternals.html#xmlDecodeEntities">xmlDecodeEntities</a><br />
+<a href="html/libxml-tree.html#xmlDocSetRootElement">xmlDocSetRootElement</a><br />
 <a href="html/libxml-entities.html#xmlEncodeEntities">xmlEncodeEntities</a><br />
 <a href="html/libxml-hash.html#xmlHashRemoveEntry">xmlHashRemoveEntry</a><br />
 <a href="html/libxml-hash.html#xmlHashRemoveEntry2">xmlHashRemoveEntry2</a><br />