Removed infolist code.

We're not using it anymore.
Removed the messages.ItemInfo class.

This has been replaced with data.item.ItemInfo
Must faster fix_html_header()

I'm not sure why, but on some header strings, the old
fix_html_header() would take forever to do the regex match and
basically hang the system for that time.  I timed it and it took about
100 seconds during which Miro was unresponsive.  The new code should
be fast enough to not do that.
bz19859: Fixed error while playing command line arguments
bz19856: fixed playback from guide sidebar
bz19463: added archive.org to the default sources list.