change libjack.py to new signature of jack_session_notify
change libjack.py to new signature of jack_session_notify

drobilla/jack1,ventosus/jack1,ventosus/jack1,drobilla/jack1,ventosus/jack1,adiknoth/tschack,ventosus/jack1,drobilla/jack1,adiknoth/tschack,drobilla/jack1