Changes to ds1820.c fixed spurious lockups... it was stopping the scheduler
and waiting for a reply from a sensor, when the sensor failed, it would lock..
All good now, just have to find out why the sensor failed.
Hop dropper code changed so that it uses the pins from the crane for testing.
HLT code: heating task was deleted when leaving the applet, removed this so that
heating is possible whilst doing other functions.