[FIX] base: when creating a database, use option 'load_language' or en_US

Make the database manager use `config['load_language']` instead of
`config['lang']`, just like the CLI option `--load-language`.  If no language
is given, install `en_US` by default.

openerp/addons/base/res/res_lang.py

@@ -32,9 +32,8 @@ class lang(osv.osv):
         found.
 
         """
-        lang = tools.config.get('lang')
-        if not lang:
-            return False
+        # config['load_language'] is a comma-separated list or None
+        lang = (tools.config['load_language'] or 'en_US').split(',')[0]
         lang_ids = self.search(cr, uid, [('code','=', lang)])
         if not lang_ids:
             self.load_lang(cr, uid, lang)

openerp/service/db.py

@@ -42,7 +42,7 @@ def _initialize_db(id, db_name, demo, lang, user_password):
         with closing(db.cursor()) as cr:
             # TODO this should be removed as it is done by RegistryManager.new().
             openerp.modules.db.initialize(cr)
-            openerp.tools.config['lang'] = lang
+            openerp.tools.config['load_language'] = lang
             cr.commit()
 
         registry = openerp.modules.registry.RegistryManager.new(