Adding upstream version 257.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

tools/xml_helper.py

@@ -0,0 +1,26 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+from lxml import etree as tree
+
+
+class CustomResolver(tree.Resolver):
+    def resolve(self, url, _id, context):
+        if 'custom-entities.ent' in url:
+            return self.resolve_filename('man/custom-entities.ent', context)
+        if 'ethtool-link-mode' in url:
+            return self.resolve_filename('src/shared/ethtool-link-mode.xml', context)
+
+        return None
+
+_parser = tree.XMLParser()
+# pylint: disable=no-member
+_parser.resolvers.add(CustomResolver())
+
+def xml_parse(page):
+    doc = tree.parse(page, _parser)
+    doc.xinclude()
+    return doc
+
+def xml_print(xml):
+    return tree.tostring(xml, pretty_print=True, encoding='utf-8')