add user settings for Sources

passbook/core/models.py

@@ -186,6 +186,12 @@ class Source(PolicyModel):
         """Return additional Info, such as a callback URL. Show in the administration interface."""
         return None
 
+    def has_user_settings(self):
+        """Entrypoint to integrate with User settings. Can either return False if no
+        user settings are available, or a tuple or string, string, string where the first string
+        is the name the item has, the second string is the icon and the third is the view-name."""
+        return False
+
     def __str__(self):
         return self.name