Quits a server.
        Required arguments:
        * server - Server to quit.
        Optional arguments:
        * reason='' - Reason for the server quitting.

def squit(self, server, reason=''):
        """
        Quits a server.
        Required arguments:
        * server - Server to quit.
        Optional arguments:
        * reason='' - Reason for the server quitting.
        """
        with self.lock:
            self.send('SQUIT %s :%s' % (server, reason))

            while self.readable():
                msg = self._recv(expected_replies=('SQUIT',))
                if msg[0] == 'SQUIT':
                    if not self.hide_called_events:
                        self.stepback()