add timing functions
synchronised playback
add delay reporting to sinks
add support for generic sinks
configure: add mach time, support for FreeBSD, check for cc and pkg-config before using
remove unused functions
fix: only sleep if delay is positive
fix: first shutdown player, otherwhise this hangs shairport on OpenBSD
clean up sync logic
tweak extension sync timing
tweak extension sync timing pt 2
Clean Up & Extension Sync Timing Merge branch 'sntp' of https://github.com/Nachtzuster/shairport into sntp

Conflicts:
	configure
	player.c
	player.h
	rtp.c
	rtsp.c