Fix watchdog for cgminer

This MR changes the watchdog.sh script a bit to use daemon-start-stop to restart the daemons.

For it to work we also need to add a /root/.cgminer/cgminer.conf file. Otherwise the miner will crash upon startup and the watchdog will just try to restart it forever. We also need to get rid of the /root/debug.log logging. Either by removing it entirely or by moving it to /var/log which we rotate every second.