The attached patch:

The attached patch:

1. Converts the shutdown driver and xend to use the store instead of
   control messages,

2. Includes Anthony's xenstore notification code, and

3. Changes xend so that sysrq's are no longer sent as "special case"
   shutdown messages.  Store keys are cheap, so making the sysrq
   delivery less obscure is good.

I think I have made all of the appropriate modifications to Xend, but
it is complex, so I may have missed something.  Comments are welcome.

Signed-off-by: Dan Smith <danms@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>