output/alsa: remove obsolete macros
PcmExport: remove obsolete API documentation
output/alsa: move alsa_configure() into the class
output/alsa: support native DSD playback

Translate SampleFormat::DSD to SND_PCM_FORMAT_DSD_U8, which was added
to alsa-lib 1.0.27.1.
output/alsa: add API documentation
ZeroconfAvahi: remove unused flag "avahi_running"

This flag is never read.
ZeroconfAvahi: remove "goto"
ZeroconfAvahi: fix coding style
output/alsa: merge Init() into Configure()
output/alsa: fix coding style
decoder/mad: simplify "return", eliminate check

This check was redundant, because we could only exit the loop when
ret==DECODE_OK.
decoder/mad: make variables more local
decoder/mad: simplify if/else chain
decoder/mad: move duplicate code to RecoverFrameError()
DecoderAPI: add decoder_seek_where_ms()

Move to fixed-point integers instead of floating point.
decoder/mad: use integer seek times

Avoid roundtrips to floating point.
decoder/modplug: use integer seek times
decoder/gme: use integer seek times
decoder/ffmpeg: use integer seek times
decoder/mp4v2: use integer seek times