- 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"?>
<CanFestivalInstance CAN_Driver="../CanFestival-3/drivers/can_socket/libcanfestival_can_socket.so"/>