Regenerate symbols and API after previous patches

* doc/symbols.xml: new global data xmlStructuredErrorContext
* doc/checkapisym.xsl: slightly improve output
* doc/* libxml2.syms win32/libxml2.def.src: regenerated the API
diff --git a/doc/devhelp/libxml2-tree.html b/doc/devhelp/libxml2-tree.html
index 6e70990..c370203 100644
--- a/doc/devhelp/libxml2-tree.html
+++ b/doc/devhelp/libxml2-tree.html
@@ -707,7 +707,7 @@
     const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> *	version	: the XML version string
     const <a href="libxml2-xmlstring.html#xmlChar">xmlChar</a> *	encoding	: the declared encoding, if any
     int	standalone	: standalone document
-    int	html	: an HTML(1)/Docbook(2) document Input stream stack
+    int	html	: an HTML(1)/Docbook(2) document * 3 is HTML after &lt;head&gt; * 10 is HTML
     <a href="libxml2-tree.html#xmlParserInputPtr">xmlParserInputPtr</a>	input	: Current input stream
     int	inputNr	: Number of current input streams
     int	inputMax	: Max number of input streams