supervise-daemon: do not use the exec_service() function
supervise-daemon: do not use the exec_service() function

In order to run healthcheck() and the unhealthy() function, add an
exec_command call to the supervisor.
Another difference is This function also logs errors instead of
attempting to display them.

This is for #271.

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