Maarten de Boer <mdeboer@iua.upf.es> - JACK plugin patch

Maarten de Boer <mdeboer@iua.upf.es> - JACK plugin patch
- now multichannel works (before only 1 channel worked). i tested stereo,
  and it works fine.

- i extended the configuration. the jack ports to connect to are now not
hard-coded anymore. instead, they will have to be specified in the
asound.conf, which allows to connect to any other jack client.

my asound.conf now looks like this:

pcm.jackplug {
        type plug
        slave { pcm "jack" }
}

pcm.jack {
        type jack
        playback_ports {
                0 alsa_pcm:playback_1
                1 alsa_pcm:playback_2
        }
        capture_ports {
                0 alsa_pcm:capture_1
                1 alsa_pcm:capture_2
        }
}