Called when a local reader is added or removed.
        Create remote pyro reader objects for added readers.
        Delete remote pyro reader objects for removed readers.

def update(self, observable, actions):
        """Called when a local reader is added or removed.
        Create remote pyro reader objects for added readers.
        Delete remote pyro reader objects for removed readers."""
        (addedreaders, removedreaders) = actions
        for reader in addedreaders:
            remotereader = RemoteReader(reader)
            self.remotereaders[reader.name] = remotereader
            name = "".join(reader.name.split(' '))
            name = ":pyscard.smartcard.readers." + "".join(name.split('.'))
            uri = self.daemon.connect(remotereader, name)
        for reader in removedreaders:
            remotereader = self.remotereaders[reader.name]
            self.daemon.disconnect(remotereader)
            del self.remotereaders[reader.name]
        self.pn.listall()