[pvr] Separate windows for TV and Radio

As discussed in #3387 this splits the Live TV section in it's TV and Radio part, each with it's own windows.
It would be nice if i get some feedback @opdenkamp @da-anda

![screenshot000](https://f.cloud.github.com/assets/1878991/1485819/4da35cd0-471a-11e3-8bdb-1b24cdd8d74a.png)