etcd when used in federated setups, currently
mandates that all clusters should have same
config.json, which is too restrictive and makes
federation a restrictive environment.
This change makes it apparent that each cluster
needs to be independently managed if necessary
from `mc admin info` command line.
Each cluster with in federation can have their
own root credentials and as well as separate
regions. This way buckets get further restrictions
and allows for root creds to be not common
across clusters/data centers.
Existing data in etcd gets migrated to backend
on each clusters, upon start. Once done
users can change their config entries
independently.