Implement the ceph osd destroy feature in ceph-deploy.

    1. handle osd already out
    2. handle osd did not blong any hostname
    3. handle osd is not in acting set

Usage: ceph-deploy osd destroy <hostname> --osd-id <osd-id>

I think it may be helpful for someone new to ceph who want to destroy osd.
If you have any questions, feel free to let me know.

Thanks!!

isn't `stop` distro specific? or does it work in every distro?