Add DBus.Properties.PropertiesChanged signal to generated API

New Tp spec is going to exist soon that uses PropertiesChanged instead of
custom change notification, so we need to support this in tp-glib.

docs/reference/telepathy-glib-sections.txt

@@ -321,6 +321,7 @@ tp_svc_dbus_properties_return_from_get
 tp_svc_dbus_properties_return_from_get_all
 tp_svc_dbus_properties_return_from_set
 tp_svc_dbus_properties_set_impl
+tp_svc_dbus_properties_emit_properties_changed
 tp_svc_properties_interface_get_properties_impl
 tp_svc_properties_interface_return_from_get_properties
 tp_svc_properties_interface_implement_get_properties
@@ -2977,6 +2978,8 @@ tp_cli_dbus_properties_callback_for_get_all
 tp_cli_dbus_properties_callback_for_set
 tp_cli_dbus_properties_run_get
 tp_cli_dbus_properties_run_get_all
+tp_cli_dbus_properties_signal_callback_properties_changed
+tp_cli_dbus_properties_connect_to_properties_changed
 tp_cli_dbus_properties_run_set
 </SECTION>
 

telepathy-glib/dbus-properties.xml

@@ -23,6 +23,13 @@
         <arg direction="out" type="a{sv}" name="Properties"/>
       </method>
 
+      <signal name="PropertiesChanged"
+              tp:name-for-bindings="Properties_Changed">
+        <arg type="s" name="Interface_Name"/>
+        <arg type="a{sv}" name="Changed_Properties"/>
+        <arg type="as" name="Invalidated_Properties"/>
+      </signal>
+
     </interface>
   </node>