docker: osd, do not use priviledged container anymore

docker: osd, do not use priviledged container anymore

Oh yeah! This patch adds more fine grained control on how we run the
activation osd container. We now use --device to give a read, write and
mknodaccess to a specific device to be consumed by Ceph. We also use
SYS_ADMIN cap to allow mount operations, ceph-disk needs to temporary
mount the osd data directory during the activation sequence.

This patch also enables the support of dedicated journal devices when
deploying ceph-docker with ceph-ansible.

Depends on https://github.com/ceph/ceph-docker/pull/478

Signed-off-by: Sébastien Han <seb@redhat.com>