Remove unused callback. In fact timer are more usefull than CB. so

git-svn-id: https://redmine.imt-atlantique.fr/svn/xaal/code/Python/branches/fork@1774 b32b6428-25c9-4566-ad07-03861ab6144f

lib/xaal/lib/core.py

@@ -42,7 +42,6 @@ class Engine(object):
         self.devices = []                        # list of devices / use (un)register_devices()
         self.started = False                     # engine started or not
         self.running = False                     # engine is running or not
-        self.callbacks = []                      # functions to call every loop
         self.timers = []                         # functions to call periodic
         self.__last_timer = 0                    # last timer check
 
@@ -230,25 +229,6 @@ class Engine(object):
         except XAALError as e:
             logger.error(e)
 
-    #####################################################
-    # Callback
-    #####################################################
-    def add_callback(self,func):
-        """ register a function to call at every engine loop"""
-        self.callbacks.append(func)
-
-    def remove_callback(self,func):
-        """ remove a given callback """
-        self.callbacks.remove(func)
-
-    def process_callbacks(self):
-        """ process registered callbacks """
-        for func in self.callbacks:
-            try:
-                func()
-            except CallbackError as e:
-                logger.error(e.description)
-
     #####################################################
     # timers
     #####################################################