Set party lang as a configuration option

configuration.py

@@ -14,5 +14,8 @@ class Configuration(ModelSingleton, ModelSQL, ModelView):
             ('company', 'in', [Eval('company'), False]),
             ('code', '=', 'party.party'),
         ], required=True))
+    party_lang = fields.Property(fields.Many2One("ir.lang", 'Party Language',
+        help=('The value set on this field will preset the language on new '
+            'parties')))
 
 Configuration()

configuration.xml

@@ -11,6 +11,8 @@ this repository contains the full copyright notices and license terms. -->
                 <form string="Party Configuration">
                     <label name="party_sequence"/>
                     <field name="party_sequence"/>
+                    <label name="party_lang" />
+                    <field name="party_lang" widget="selection" />
                 </form>
                 ]]>
             </field>

party.py

@@ -87,6 +87,11 @@ class Party(ModelSQL, ModelView):
                     'write_uid', 'write_date'])
         return [address_obj.default_get(fields_names)]
 
+    def default_lang(self):
+        config_obj = self.pool.get('party.configuration')
+        config = config_obj.browse(1)
+        return config.party_lang.id
+
     def on_change_with_vat_code(self, vals):
         return (vals.get('vat_country') or '') + (vals.get('vat_number') or '')