[sheepdog] killing sheep is unsafe - sheep: add option to create pid file

[Liu Yuan]

On 07/18/2012 06:43 PM, Jens WEBER wrote:
> sheep doesn't respond correctly on kill TERM (15) signal and crash. I
> think this is the reason of my problem and potential cause lost of
> data.

I am thinking of adding a new collie command,

 collie node kill node_id

can this meet the needs to shutdown the specific node? I don't want to
implement a signal handler for TERM, because we don't want worker
threads to handle signals as normal.

Thanks,
Yuan