Added a systemd target for ceph

ceph now has a target structure for systemd
set boot up sequence after network-online.target local-fs.target for mon osd and mds
Thanks to tserong@suse.com for correcting the target behaviour.

Signed of by Owen Synge - osynge@suse.com
rcceph: wrapper for ceph systemd

systemd is easy to use if you have a wrapper.
message showing available paramters to rcceph.
Also check for directories contianing mon/osd deamon settings.
Added suport for chkconfig using LSB Header

Signed off by osynge@suse.com
systemd support in ceph-disk activate

previous code just fails for systemd with an error
udev rules now explicitly specify init system

ceph-disk detects OS and Version and from this decides
to use sysV systemd or upstart. This code needs a bigger
rewrite so for now just explicitly tell ceph-disk the
init system.