Use the functions song_save() and song_load() to use the same format
as in the database file for those songs which need the tags.

Don't try db_get_song() if the URI has a scheme.

The only caller doesn't use its return value, and the value isn't
useful anyway.

After we've been hit by Large File Support problems several times in
the past week (which only occur on 32 bit platforms, which I don't
have), this is yet another attempt to fix the issue.

This updates the copyright header to all be the same, which is
pretty much an update of where to mail request for a copy of the GPL
and the years of the MPD project. This also puts all committers under
'The Music Player Project' umbrella. These entries should go
individually in the AUTHORS file, for consistancy.

"ls" is a bad name for a library which parses URIs.  We'll move the
rest of the "ls" library later.

Create a new library which saves/loads the queue to/from the state
file.