remove the osd service

There are two undesirable behaviours of managing the osd services:
  1. Whenever ceph.conf changes, every single osd in your cluster will restart. It is better to coordinate this manually.
  2. Whenever an OSD exits (say, for a broken disk) puppet will restart the daemon. Better to leave the daemon crashed and fix manually.
Merge branch 'master' into unmanaged_osd_service
remove other test for presence of the osd service