2.0

Hi, I created the base request types for integration with OkHttp for 2.0

I decide create a new package for better organization and to avoid conflicts with existing code, so we can maintain the current Apache client and OkHttpClient on the same side.

I try keep changes small but OkHttp use HttpURLConnection instead of Apache client so I do the best I can, and for this first aproach is the basic.

I don't now gradle plugin so well so I added the last OkHttpClient on the libs folder, but he can be deleted.