Implement sleep lifecycle check

Signed-off-by: Maxime Petazzoni <max@signalfuse.com>
Use multiprocessing.pool instead of multiprocessing.dummy

Signed-off-by: Maxime Petazzoni <max@signalfuse.com>
Make orchestration threads daemon and detect error status when waiting for them

Signed-off-by: Maxime Petazzoni <max@signalfuse.com>