Shutting down X with control+alt+backspace

[Luke Dean]

This is an answer to a question I started to post, but then decided to
research instead.  I know many readers of this list use the feature I'm
describing.

When Xorg was upgraded to version 7.4, the historic ability to shut down X
with Control+Alt+Backspace became a non-default option.  The solution to
re-enabling this behavior was to add
 	Option "DontZap" "off"
to the ServerLayout or ServerFlags section of xorg.conf as documented in
a note in the Handbook 
http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/x-config.html

A few days ago, x11/xkeyboard-config was upgraded to 1.6 and the solution
in the Handbook is no longer sufficient.

The new solution that gets Control+Alt+Backspace working for me
again is to add
 	Option  "XKbOptions" "terminate:ctrl_alt_bksp"
to the "InputDevice" section of xorg.conf.