fix parameter inheritance using MRO

+ no update on unhchanged values within 1 sec

Change-Id: I3e3d50bb5541e8d4da2badc3133d243dd0a3b892

secop/protocol/dispatcher.py

@@ -61,6 +61,8 @@ def make_update(modulename, pobj):
 
 class Dispatcher:
 
+    OMIT_UNCHANGED_WITHIN = 1  # do not send unchanged updates within 1 sec
+
     def __init__(self, name, logger, options, srv):
         # to avoid errors, we want to eat all options here
         self.equipment_id = options.pop('id', name)