uaudio WIP

[Mathew Kanner]

Hello All,
	The following patch

	http://www.cnd.mcgill.ca/~mat/uaudio-netbsd177.diff.bz2

	is a work is progress.  It brings in line with the latest
uaudio code from NetBSD and allows me to play using my USB audio
device.  It has tons of debugging output and extra delays and it still
panics my kernel sometimes.  I had to comment out the mixer because it
was muting my output.
	The patch changes the way pcm probes for endpoints using
provided code instead of trying ourselves.  It also reports a slightly
more correctly supported range of speeds instead of assuming that we
support all possibilities.

	I would really like to hear if it works for anybody else.

	--Mat
-- 
	sig machine broken