added dns specific rules for postfix on the monitor server
added the uid to output rules for sending smtp
changed the hard coded port in the mon iptables rules to use the smtp_port variable instead
added IP addresses the the app and mon vm in the vagrant file
moved defining the dns IP to the environment specific yml files and removed it from the global variable yml file
Merge pull request #677 from dolanjs/iptables_dns_denies

iptables rule fixes for prod mon server