bug-fix devicelist method

function/__init__.py

         if self.__devices__ is None:
             self.__devices__ = []
             for name, obj in inspect.getmembers(self):
-                if obj.__class__.__module__.split('.')[0] == 'function':
+                if obj.__class__.__module__ == "devices":
+                    self.__devices__.append(obj)
+                elif obj.__class__.__module__.split('.')[0] == 'function':
                     for devicename, device in inspect.getmembers(obj):
                         if device.__class__.__module__ == "devices":
                             self.__devices__.append(device)