Health checks are a way to monitor a service and make sure it stays
healthy.
If a service is not healthy, it will be automatically restarted after
running the unhealthy() function to clean up.
The --retry option for supervise-daemon defines how the supervisor will
attempt to stop the child process it is monitoring. It is defined when
the supervisor is started since stopping the supervisor just sends a
signal to the active supervisor.
This fixes#160.
This creates --respawn-delay, --respawn-max and --respawn-period. It was
suggested that it would be easier to follow if the options were
separated.
This is for #126.
Allow limiting the number of times supervise-daemon will attempt to respawn a
daemon once it has died to prevent infinite respawning. Also, set a
reasonable default limit (10 times in a 5 second period).
This is for issue #126.