"sticky" xkb options ?

[Matthieu Herrb]

Hi,

In order to keep the oldctrl+alt+backspace sequence killing X by
default, I'm looking for the best place to place the configuration
option. I'd like to put it in /etc/X11/xorg.conf.d/00-killserver or
similar.

Unfortunatly, at least with xserver 1.9 or 1.10, 
'Option "XkbOption" "terminate:ctrl_alt_bksp"' doesn't stick.
Any other 'Option "XkbOption" "..."' parsed later will clear the
already set options.

The same is true for any initialisation done inside the xserver code
itself via add_option(). 

Is there a way to set a sticky xkbOption ?
-- 
Matthieu Herrb