UI Update: Main Menu and Streams

Updates made to the UI:
- Holo Light theme
- Creates a main menu which allows the user to authenticate and select which stream they would like to view
- Stream views updated to a card layout

![ui_update_menu](https://cloud.githubusercontent.com/assets/3380092/3705645/9023d3da-1421-11e4-98e2-485d8e00b242.png)
![ui_update_stream](https://cloud.githubusercontent.com/assets/3380092/3705646/90299d92-1421-11e4-837d-88cf61a1cfaf.png)

I'm easy on this. One side of me says `WeakReference`s shouldn't be exposed and the other half says `newInstance` it