added firewall checks and notices

added firewall checks and notices
added extra views for a simple and detailed view for sites
added firewall_notice to emailTxt
added extra fields for firewall, external_dns_status, as well as several other
	fields reserved for future use, such as traceroute, uptime and rpms.
updated policy to act on firewalled nodes
add dependency on 'nc' netcat for a more reliable nmap, port probing utility.

reorganized scanapi.py, hopefully can generalize this further in the future.