Replaces GLib's GError.

.. instead of rolling own classes.

The "bool" type is built-in.

Improve error reporting and handling.  command.c gets the new function
print_error(), which sends a GError to the client.

Reduce header dependencies.

These fixes were mostly generated with `codespell' [0] and manually
reviewed.

[0] http://git.profusion.mobi/cgit.cgi/lucas/codespell/

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.

Don't declare and export variables specific to stored playlists in
playlist.c/playlist.h.

On some systems, the time_t data type was not present, because
stored_playlist.h didn't include the time.h header directly.

The function deletePlaylist() shouldn't be in playlist.c.

Don't use our deprecated linked list library, use GLib's GPtrArray
instead.

Pass index arguments as unsigned integers.  They must not be negative,
and even if some caller accidently passes -1, it won't pass the bound
checks (since it's now 2**32-1).

spl_list() provides an interface for enumerating all stored playlists.
This separates the internal playlist logic from the protocol specific
function lsPlaylists().

The return value of spl_append_uri() was somewhat buggy: some branches
returned ACK_* values, and some an enum playlist_result.  Unify this.

Rename addToStoredPlaylist() to spl_append_uri(), and remove the
clearStoredPlaylist() macro.

The two functions clearStoredPlaylist() and addToStoredPlaylist()
don't belong into playlist.c.  clearStoredPlaylist() was a wrapper for
spl_clear(), and is converted into a CPP macro for now.

Renamed all public functions, prefix is "spl_".

No CamelCase in file names.

Again, a data type which can be forward-declared.

Return an "enum playlist_result" value instead of calling
commandError() in storedPlaylist.c.

Try to only include headers which are really needed.  We should
particularly check all "headers including other headers".  The
long-term goal is to have a manageable, small API for plugins
(decoders, output) without so many mpd internals cluttering the
namespace.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7319 09075e82-0dd4-0310-85a5-a0d7c8717e4f

Abstractions should reduce the amount of code and make things
easier to follow.  The StoredPlaylist struct did not do that, so
get rid of it and just use our standard linked list
implementation instead.

diffstat agrees with me that the abstraction is pointless:
3 files changed, 60 insertions(+), 90 deletions(-)

git-svn-id: https://svn.musicpd.org/mpd/trunk@7120 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@7119 09075e82-0dd4-0310-85a5-a0d7c8717e4f

git-svn-id: https://svn.musicpd.org/mpd/trunk@6246 09075e82-0dd4-0310-85a5-a0d7c8717e4f

new commands: playlistmove and playlistdelete.

git-svn-id: https://svn.musicpd.org/mpd/trunk@6116 09075e82-0dd4-0310-85a5-a0d7c8717e4f