Standardize

This makes Dvash into a more standard Ruby project. Note the namespacing and abstraction. There is still a bit todo (Preparing IPtables, using `ipfw` instead of iptable on Mac) but this should get you on your way.

I'm running on Linux, so I get stopped right at "No ipv6tables found, we can't block IPv4 addresses!", so I cannot test this code further than that but I suggest that you take from this and learn how to make a more "standard" Ruby project.

> Good work, BTW!