Write down thoughts on V2 of Electric Slide

ping @JustinAiken @benlangfeld 

This is my attempt to describe the API for how I think ElectricSlide should work.  I've taken a look at existing ElectricSlide implementations and realized that the plugin wasn't doing enough, resulting in a lot of code being copy/pasted. The goal is to make it so you can declare queues and consume them with just a few lines, rather than have agent selection logic scattered throughout the app and the library.

Please review the [README](https://github.com/adhearsion/electric_slide/blob/v2/README.markdown) especially to see where my thinking is going and offer any feedback you may have.