Added option for reverse lookups

Hi Ryan,
We've been having issues for some time with our corporate proxy and sending CONNECT requests using numerical IPs instead of hostnames. I've been playing with reverse lookups using a local DNS which builds its own in-addr.arpa zone by monitoring DNS responses passing by with tcpdump|sed|nsupdate.
There is also a sample upstart script I've been using in Ubuntu for a while.
Troy.