Inteface Changes/Updates about servo

[brharrington]

I pushed my changes to a separate branch, brhdev. You can see the changes from the master branch:

master...brhdev

The only dependency I added was guava. I started from scratch with the interfaces and gradually pulled in things from the old code base so there are quite a few small diffs. My plan is to create a few basic implementations for the main interfaces (filter, poller, writer) to make sure they will work well in practice for my use cases. I'll also add some test cases and comments.

For now I just put everything in the same package since I was mostly worried about the interfaces. I'll clean that up, but I figured I would look at some of the other netflix projects here to see what conventions are used first.