Audio - In kernel audio mixing

[Nathanial Sloss <nat%netbsd.org@localhost>]

Hi,

I've made changes to in kernel audio mixing and made them available at 
ftp.NetBSD.org/pub/NetBSD/misc/nat/nextaudio5-kern.gz

This patch includes only changes to audio the synthesized spkr device will be 
in a follow up email.

New in this version a new audio ioctl to select your audio channel based on 
process id of it's controlling process, changes to audioctl(1) to demonstrate 
this.

/dev/sound keeps setting of the last process that changed parameters and it is 
possible to use audioctl(1) on /dev/sound to set parameters before opening 
/dev/sound.

Simultaneous recording channels with independent volume / recording paraeter 
control.

Also a sysctl to set the common format use full for when hw available 
precision and or channels are greater than 2ch 16 bit 44100 Hz.

Please take a look, if there are no objections I would like to commit this in 
two weeks.

Best regards,

Nat