supervise-daemon: redirect std{in,out,err} to /dev/null after demonizing
supervise-daemon: redirect std{in,out,err} to /dev/null after demonizing

This fixes #239.

williamh/openrc,dwfreed/openrc,OpenRC/openrc,williamh/openrc,OpenRC/openrc,dwfreed/openrc,dwfreed/openrc,OpenRC/openrc,williamh/openrc