Patch to support OSSv4 Mixer

This patch allows moc to use the OSSv4 per-application mixer API.

Within this API, '/dev/mixer' is no more needed, as the ioctl is called directly to '/dev/dsp', and sets the volume only for moc, not the global system volume.

This API is supported by 4Front reference OSS implementation, and by FreeBSD-current stock implementation.

Works at the lastest svn, thanks!
I put it into the moc-svn aur package, too:

Thanks, I've committed your patch to the SVN.