Update to upstream version 0.21.2
Details:
- Major upgrade from 0.20.x branch, see upstream log: https://raw.githubusercontent.com/MusicPlayerDaemon/MPD/v0.21.2/NEWS
- Use meson build system
- Revamp OPTIONS:
- Retire all options without LIB_DEPENDS
- Rename AAC option to FAAD, as aac is also available via FFMPEG
- New OPTIONS for ISO9660 and ZZIP; bzip support is always compiled in
- Support for commercial streaming services: QOBUZ, SOUNDCLOUD, TIDAL
- Simplify Makefile when possible
- Pet portlint