SBS for Python-Iview
* Overrides all the ABC Iview function, you only get SBS instead
* I hacked the internal interface for the list items in order to get the
front end to display multiple tree branches for the one SBS XML file, but
it should be done in a nicer way.
* Only works with the GTK version; probably breaks the CLI version
* I don’t think I ever finished the “Copy URL” button idea. But it would be
nice to be able to quickly pipe a URL into a video player and stream it
without worrying about downloading it.