The default is always UTF-8.

Always write UTF-8 to the log file.

Don't define HAVE_FS_CHARSET, and make GetFSCharset() return "ACP"
instead of "UTF-8".  Ignore the configuration setting, which had no
effect anyway.

Stupid mistake from commit 7cb803ad

Move code from the "vorbis" decoder.

Improve initial seek by not reading/decoding the first frame before
checking for the seek command.

Convenient method that behave differently than Read, and that will be used by
tag scanners.

This method will return in case of error, if the whole data is read or is EOF
is reached.

Fixes missing SongBorder() call, which causes "single" mode breakage.

If there's a stream tag, don't let the song tag override it in the
next update_stream_tag() call.

If the song tag comes from a stream, and MPD playback restarts, MPD
would believe the tag should override the newly received tag.  This
makes the previous tag appear stuck.  This change passes the song tag
only if it's authoritative - i.e. if it's a song file.

Reduce runtime overhead.

Right after booting, the monotonic clock starts with a very small
value, and AudioOutput::LockUpdate() may believe that the fail_timer
has not recovered yet.