ncm-ceph: fixes for issues #224 and #226

add osd_objectstore
Use of recent perl idioms #224
component slow to run for large numbers of OSDs on small number of servers + logging #226
why not a `run_command_as_ceph_with_ssh`, a dedicated emthod for running commands as cephuser via ssh? not need then for the extra `use` and `SSH_COMMAND` export.