//if the extruder motor is idle for more than SECONDS, and the temperature over MINTEMP, some filament is retracted. The filament retracted is re-added before the next extrusion
//or when the target temperature is less than EXTRUDE_MINTEMP and the actual temperature is greater than IDLE_OOZING_MINTEMP and less than IDLE_OOZING_FEEDRATE
//or when the target temperature is less than EXTRUDE_MINTEMP.