Get a server socket

def get_server_sock():
    "Get a server socket"
    s = _socket.socket()
    s.setsockopt(_socket.SOL_SOCKET, _socket.SO_REUSEADDR, True)
    s.setblocking(False)
    s.bind(('0.0.0.0', _config.server_listen_port))
    s.listen(5)
    return s