allow crush map bucket definition or don't start OSDs

[abonillabeeche]

If buckets (racks, dc, row, etc) are created post deployment, additional nodes added post-deployment will not have those attributes and the cluster will not re-deploy to a healthy state. Options I see:

• We need to have a hierarchical system to define placement of hosts, or;
• When new/additional nodes are added to the storage after the initial deployment, the OSDs should be created BUT not started - this to allow the administrator to move those OSDs/hosts to the correct bucket before starting the OSD processes.