Sorting

This will add sorting capabilities to the browse view. It will be possible to sort the list by title (default), rating and date (created/lastupdate). New sorting will only be accessible if the config option "orderallbydisk" is NOT set, since this would overwrite sorting anyway. 

GUI changes for Nexgen:
![nexgen](https://f.cloud.github.com/assets/635837/1754201/ef68adfe-664b-11e3-90b9-3e97856bcb4e.png)

GUI changes for Elegant:
![elegant](https://f.cloud.github.com/assets/635837/1754202/f9df7d76-664b-11e3-8a49-ccf88f88f553.png)

Language definition for "order" will be needed. I already added it to de.php and en.php.