Enables the "Format" row in "playlistinfo" responses.

https://github.com/MusicPlayerDaemon/MPD/issues/1094

Bug #915 is about an I/O exception thrown where none was allowed,
leading to crash via std::terminate().  However, instead of catching
and logging the error inside the decoder plugin, it should be able to
propagate the I/O error to the MPD core, so MPD can avoid trying other
decoder plugins.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/915

The ones in std have overloads for const char/char.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

The former was deprecated with C++14.

According to the C++11 and C++17 standards, both files are identical.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Fixes another build failure.

This attribute is not a URI; it is just the filename without its
parent directory path.  To avoid confusion, let's rename it to
"filename", leaving the struct without a "uri" attribute.

Preparing to move logger calls out of lower-level libaries, and
propagating error details to the caller instead.

And specify whether generic tags are being scanned.

This code has been moved to LoadFromArchive().

Load APE/ID3 tags from archives.

This commit adds support for APE/ID3 tags from NFS/SMB files.

See http://bugs.musicpd.org/view.php?id=4270