[hobbit] Do not display "memory"

[Xavier PAJONA <xavier.pajona (at) prod.steria.fr>]

Hi all,
I use a hobbit client on a linux server, but for some reason it doesn't 
make sense to monitor the memory usage.
I can't seem to find a way not to monitore one of the "base" tests of 
the linux hobbit client, like memory for instance. I could use a 
"group-except" in the bb-host file, but I don't like the idea of the 
memory being monitored but not displayed, I'd really like it not to be 
tested at all.
Any idea how to do this ?
Thanks.
Xavier