Add traking on warn fields

WORK IN PROGRESS: port hr_holidays_usability

hr_holidays_usability/hr_employee_view.xml

@@ -1,11 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
-  Copyright (C) 2015 Akretion (http://www.akretion.com)
+  © 2015-2017 Akretion (http://www.akretion.com)
   @author: Alexis de Lattre <alexis.delattre@akretion.com>
-  The licence is in the file __openerp__.py
+  License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
 -->
-<openerp>
-<data>
+<odoo>
 
 <record id="view_employee_form_leave_inherit" model="ir.ui.view">
     <field name="name">hr_holidays_usability.hr.employee.form</field>
@@ -14,16 +13,15 @@
     <field name="arch" type="xml">
         <!-- too difficult to hide the inside of the Leave group
         so I hide the whole group and re-create one -->
-        <group string="Leaves" position="attributes">
+        <xpath expr="//field[@name='remaining_leaves']/../.." position="attributes">
             <attribute name="invisible">1</attribute>
-        </group>
-        <group string="Leaves" position="after">
+        </xpath>
+        <xpath expr="//field[@name='remaining_leaves']/../.." position="after">
             <group name="holidays" string="Holidays">
                 <field name="holiday_exclude_mass_allocation"/>
             </group>
-        </group>
+        </xpath>
     </field>
 </record>
 
-</data>
-</openerp>
+</odoo>