xkb rules for Thinkpad extra keys

[Hile Tuohela <hile@iki.fi>]

I have written a small set of xkb rules to enable the extra keys
on thinkpad laptops (keysyms 233 and 234). The rules implement 
new keyboard model 'thinkpad'.

The files are available with a html README from 
http://hile.dyndns.org/xkb-thinkpad.tgz

You can probably just run diff for the files under xkb directory,
the changes are quite trivial. It would be great if these configs
would end up being part of the packages and upstream. 

There might be problems with the rules and the fact these rules 
replace the pc101,pc102 and other 'model' parameters in XF86Config-4,
works for me at least with finnish keyboard.

I think my mapping of 'Prev/Next_Virtual_Screen' is good to not mix
the keys with any other, possibly used keys, and most likely map 
nicely to the tasks most people would do with these keys now: I see
no other use for these keys except virtual desktop switching and 
window moving.

    *hile*