Sorting movie and tv shows list under xbmc

Sorting is very much needed for large libraries, so I added support for it. The various sorting options can very easily be extended, just edit xbmc.html.
Currently, it won't affect music list. Ideally the sorting button would be located under or to the right of the tabs "movies", "tv shows" and "music", perhaps with different sorting options for each tab. But I think this works fine for now.

![ss](https://f.cloud.github.com/assets/5490330/1557231/56083360-4f07-11e3-9fe9-276d0902caa1.png)