replaygain/ffmeginput.cpp: build with ffmpeg7
tags/tags.cpp: update for taglib 2.0 id3v2tags
mpd-interface/mpd.conf.template: update mpd.conf.template (added conductor)

check https://github.com/spectromas/cantata
check https://github.com/heirecka/cantata
check https://github.com/cris-b/cantata (ffmpeg)
check https://github.com/fenuks/cantata (good guy, ffmpeg, taglib)
check https://github.com/nrndda/cantata (large numbers)
check https://github.com/dimibyte/cantata (cue parser)
check https://github.com/mcilloni/cantata (taglib)
check https://github.com/nullobsi/cantata
