[FIX] auth_oauth: login with Facebook

Configuration:
  - Change the scope to: user_profile,email
  - Change the validation url to 'https://graph.facebook.com/me' that returns
    more information about the user.

Facebook open graph API does not send the expected 'user_id' parameter, need to
use the 'id' key.

Fixes #5546
Closes #7532

addons/auth_oauth/auth_oauth_data.xml

@@ -14,8 +14,8 @@
         <record id="provider_facebook" model="auth.oauth.provider">
             <field name="name">Facebook Graph</field>
             <field name="auth_endpoint">https://www.facebook.com/dialog/oauth</field>
-            <field name="scope"></field>
-            <field name="validation_endpoint">https://graph.facebook.com/me/permissions</field>
+            <field name="scope">public_profile,email</field>
+            <field name="validation_endpoint">https://graph.facebook.com/me</field>
             <field name="data_endpoint"></field>
             <field name="css_class">fa fa-facebook-square</field>
             <field name="body">Log in with facebook</field>

addons/auth_oauth/res_users.py

@@ -101,7 +101,12 @@ class res_users(osv.Model):
         validation = self._auth_oauth_validate(cr, uid, provider, access_token)
         # required check
         if not validation.get('user_id'):
-            raise openerp.exceptions.AccessDenied()
+            # Workaround: facebook does not send 'user_id' in Open Graph Api
+            if validation.get('id'):
+                validation['user_id'] = validation['id']
+            else:
+                raise openerp.exceptions.AccessDenied()
+
         # retrieve and sign in user
         login = self._auth_oauth_signin(cr, uid, provider, validation, params, context=context)
         if not login: