debian: move ceph-rest-api from ceph-common to ceph

ceph-rest-api is a 'server' thing that runs persistently; 'ceph' is a
better match.

Signed-off-by: Sage Weil <sage@inktank.com>
debian: make ceph-common own etc/ceph, var/log/ceph

Clients can make use of these directories, and ceph-common is required by
ceph, so nothing should break here.

Change the purge postrm script to be for ceph-common (it does nothing else).

Signed-off-by: Sage Weil <sage@inktank.com>
debian: move rbdmap config and sysvinit/upstart scripts into ceph-common

Fixes: #7171
Signed-off-by: Sage Weil <sage@inktank.com>
debian: fix control to allow upgrades

Signed-off-by: Mohammad Salehe <salehe+dev@gmail.com>
Merge pull request #1581 from ceph/wip-init

a few deb changes