Fix --device bug

Fix --device bug

Duuuh, the --device option never worked because "plug:swmix" was harcoded
in play.c instead of using the value from the configuration. Even worse,
the default in play.ggo was _also_ set to "plug:swmix". Replace that by
"plughw:0,0".

This patch also simplifies and optimizes play_pcm().

Anyway, software mixing is still recommended. Here's an aprropriate
/etc/asound.conf:

---------------------------------------------------- /etc/asound.conf
pcm.swmix {
	type dmix
	# any unique number here
	ipc_key 313
        ipc_perm 0666

	slave {
		pcm "hw:0,0"
		# these settings may require tweaking for different sound
		# cards; this is for the Powerbook's built-in snd-powermac
		# probably not required at all for well-behaved cards...
		period_time 0
		period_size 1024
		buffer_size 8192
		# mentioning rate fixes wrong speed/pitch in native ALSA stuff
		# rate 44100
	}
}

pcm.dsp0 {
	type plug
	slave.pcm "swmix"
}

ctl.mixer0 {
	type hw
	card 0
}

pcm.!default {
	type plug
	slave.pcm "swmix"
}
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a Use the
: Use a large input
buffer and For one, the