Prepare for ID3 support on userspace NFS/SMB/CIFS mounts.

Omit the file size check if we don't know the size.

Apply padding only to the fseek(), not to the chunk size.  This fixes
bogus "failed to read riff chunk" messages when the last chunk has an
odd size.

See http://bugs.musicpd.org/view.php?id=4486

Some tagging libraries (eg. TagLib) produce that variant.

Replacing GLib macros.

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

Make sure we get a UTF-8 encoded string.

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

On 32 bit systems with large file support enabled (i.e. "sizeof(off_t)
> sizeof(size_t)") gcc emits a warning because a size_t cast to off_t
can never become negative.

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.

[mk: cast off_t to uint32_t; same fix for aiff.c]

Added a small AIFF parser library, code copied from the RIFF parser
(big-endian integers).  Look for an "ID3" chunk, and let libid3tag
parse it.

Added a small RIFF parser library.  Look for an "id3" chunk, and let
libid3tag parse it.