Disconnect a receiver from a signal.
        Signal and receiver must exist, otherwise an exception is thrown.

        :param receiver: Name of the receiver

def disconnect(self, receiver):
        """
        Disconnect a receiver from a signal.
        Signal and receiver must exist, otherwise an exception is thrown.

        :param receiver: Name of the receiver
        """
        if receiver not in self.receivers.keys():
            raise Exception("No receiver %s was registered" % receiver)
        self.receivers[receiver].disconnect()
        del(self.receivers[receiver])
        self.__log.debug("Receiver %s disconnected" % receiver)