Add internationalization

[DerPipo]

These strings are hardcoded:

• "Track %d of %d"
• "Hi-Speed Scrubbing"
• "Half-Speed Scrubbing"
• "Quarter-Speed Scrubbing"
• "Fine Scrubbing"

I don't know what's the best way to do this, but i think adding I18N to the bundle would be a nice one. Then we could use NSLocalizedStringFromTableInBundle(...). By adding a NSBundle property to the view controller also the resource loading would be better, because if the bundle name changes you only need to modify one line of code.