Updated Debian guide

[Niels Serup]

I just updated the Debian guide on http://en.qi-hardware.com/wiki/Debian

It had become very messy and was missing crucial information.
Also, in the past few weeks, it seems that more and more have been
troubled by sound issues, etc.

Those of you who're using Debian, please take a look at the new
information and change whatever you think lacks something.


Niels