- now call load, start, free PLC from the python Thread

- add a wx timer (500ms) that pull the plc state to refresh Beremiz icons
(fix problem when command PLC with the TaskBar icon)

<?xml version="1.0" encoding="UTF-8"?>
<CanFestivalSlaveNode CAN_Device="vcan0" CAN_Baudrate="125K" NodeId="3" Sync_Align="100"/>