[Sheepdog] Sheepdog client is merged into QEMU main tree

[MORITA Kazutaka]

Hi all,

The Sheepdog client is merged into the QEMU mainline.  From now on,
please use the mainline tree to use the sheepdog client:

  git://git.sv.gnu.org/qemu.git


Also, I think this would be a good time to check our remained TODOs
and Sheepdog release plan.  I'll send them after I fix some server
problems.

Thanks,

Kazutaka