Unpolute FSharp.Data namespace

@tpetricek, regarding #477, what about this:

Before:
![image](https://f.cloud.github.com/assets/738761/2305416/2909889e-a256-11e3-9198-d3a3b491add9.png)

After:
![image](https://f.cloud.github.com/assets/738761/2305418/30b7b4a8-a256-11e3-8f19-af3350588d90.png)