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 function was not present in SQLite < 3.4.

sticker_delete_value() deletes only one value in a sticker, while
the old function sticker_delete() deletes all values.

sticker_find() finds stickers with the specified name.

Simplify initialization and finalization.

Turn the "return false" error handlers into "return NULL".

Moved the hash table initialization from sticker_list_values() to the
new function sticker_new().  This fixes a memory leak in
sticker_list_values().

sticker_list_values() is only used internally in sticker.c.  Remove
sticker_song_list_values() completely, it is superseded by
sticker_song_get().

The sticker struct can be used for enumerating values.  This will
replace the sticker_list_values() function.

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: merged memory leak patch; fixed indentation (tabs); fixed
documentation typo]

"Stickers" are pieces of information attached to existing MPD objects
(e.g. song files, directories, albums).  Clients can create arbitrary
name/value pairs.  MPD itself does not assume any special meaning in
them.