[gxml] Ported Serializable.serialize_unknown_property_type signal to GXml.Node

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 5eec9f20310a9cae82c4fc09eb753dba5e9bcd27
Author: Daniel Espinosa <esodan gmail com>
Date:   Wed Apr 29 10:31:30 2015 -0500

    Ported Serializable.serialize_unknown_property_type signal to GXml.Node

 gxml/Serializable.vala     |    2 +-
 test/SerializableTest.vala |    3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/gxml/Serializable.vala b/gxml/Serializable.vala
index a85065c..67ce8bb 100644
--- a/gxml/Serializable.vala
+++ b/gxml/Serializable.vala
@@ -214,7 +214,7 @@ namespace GXml {
      * @param prop a { link GLib.ParamSpec} describing attribute to serialize
      * @param node set to the { link GXml.xNode} representing this attribute
      */
-    public signal void serialize_unknown_property_type (GXml.xNode element,
+    public signal void serialize_unknown_property_type (GXml.Node element,
                                                         ParamSpec prop,
                                                         out GXml.xNode node);
 
diff --git a/test/SerializableTest.vala b/test/SerializableTest.vala
index b467658..068c74c 100644
--- a/test/SerializableTest.vala
+++ b/test/SerializableTest.vala
@@ -120,8 +120,9 @@ public class SerializableCapsicum : GXml.SerializableJson {
                        assert_not_reached ();
                }
        }
-       private void serialize_unknown_property_type (GXml.xNode element, ParamSpec prop, out GXml.xNode node)
+       private void serialize_unknown_property_type (GXml.Node elem, ParamSpec prop, out GXml.xNode node)
        {
+               xElement element = (xElement) elem;
                xDocument doc = element.owner_document;
                switch (prop.name) {
                case "ratings":