Upgrade to libxml 2.9.2 and libxslt 1.1.28

third_party/libxslt/python/libxslt_wrap.h

+#include "libxml_wrap.h"
+#include <libxslt/xslt.h>
+#include <libxslt/xsltInternals.h>
+#include <libxslt/xsltutils.h>
+#include <libxslt/attributes.h>
+#include <libxslt/documents.h>
+#include <libxslt/extensions.h>
+#include <libxslt/extra.h>
+#include <libxslt/functions.h>
+#include <libxslt/imports.h>
+#include <libxslt/keys.h>
+#include <libxslt/namespaces.h>
+#include <libxslt/numbersInternals.h>
+#include <libxslt/pattern.h>
+#include <libxslt/preproc.h>
+#include <libxslt/templates.h>
+#include <libxslt/transform.h>
+#include <libxslt/variables.h>
+#include <libxslt/xsltconfig.h>
+
+#define Pystylesheet_Get(v) (((v) == Py_None) ? NULL : \
+        (((Pystylesheet_Object *)(v))->obj))
+
+typedef struct {
+    PyObject_HEAD
+    xsltStylesheetPtr obj;
+} Pystylesheet_Object;
+
+#define PytransformCtxt_Get(v) (((v) == Py_None) ? NULL : \
+        (((PytransformCtxt_Object *)(v))->obj))
+
+typedef struct {
+    PyObject_HEAD
+    xsltTransformContextPtr obj;
+} PytransformCtxt_Object;
+
+#define PycompiledStyle_Get(v) (((v) == Py_None) ? NULL : \
+        (((PycompiledStyle_Object *)(v))->obj))
+
+typedef struct {
+    PyObject_HEAD
+    xsltTransformContextPtr obj;
+} PycompiledStyle_Object;
+
+
+PyObject * libxslt_xsltStylesheetPtrWrap(xsltStylesheetPtr ctxt);
+PyObject * libxslt_xsltTransformContextPtrWrap(xsltTransformContextPtr ctxt);
+PyObject * libxslt_xsltStylePreCompPtrWrap(xsltStylePreCompPtr comp);
+PyObject * libxslt_xsltElemPreCompPtrWrap(xsltElemPreCompPtr comp);