[K12OSN] Environmental Variables per workstation

[Luis Montes]

I've written a little how-to on how to set up arbitrary environmental 
variables per workstation on k12ltsp.

http://school.qop.org/lmontes/env.html

There's definetly more than one way to do this, but I think this way is 
pretty flexible.

You can use this to assing a default printer for applications that still 
look for the PRINTER variable.

Luis