ipw driver

[Johannes Hofmann]

Now that the iwi driver has been commited, I think it is time to try to get
in the ipw driver too. A diff to current cvs can be found at
http://www.ecademix.com/JohannesHofmann/ipw.diff.gz
It is currently not using tokens to do the locking, because I do not yet 
understand the details. So it might need some more work before inclusion. 
However it does work for me for quite a while now.

  Johannes