Improve handling of ASX playlists
Basically our asx parser is broken.
- It doesn't handle relative links.
- It should also URL encode the hrefs (spaces in the url need to be converted to %0.9.x maintenance etc).
- protocol rollover, authors, title's etc etc aren't handled.
- It is still located in the old demux/m3u.c module instead of modules/demux/playlist/
See this for asx examples.