This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

If we return false, their values are undefined.

Merge duplicate symbol.

Prepare to migrate away from GLib.  Currently, we're still using GLib
as a backend.

All sources which might work with large files must include config.h,
to get Large File Support on 32 bit platforms.

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.