Ping sweep option to mark IP's as offline instead of available

The current Ping Sweep auto-discovery tool will mark IP addresses as available if they are not able to be pinged. This means that if a system is offline for maintenance or is in a cold standby state the IP will be marked as available and will be handed out when calling "api/1.0/suggest_ip".

It would be good to have an option to mark the IP addresses as online/offline instead of available/unavailable.