Soft-Index File Store: (local files)-based cache store
- see SoftIndexFileStore javadoc for design info
ISPN-4696 SuspectException kills operation on ClusterRegistryImpl

* Added retry for ClusterRegistry operations
Change ReplicatedCHFactory to only replace leavers in updateMembers()

Uneven primary ownership should be dealt with in rebalance() only.
Delegate the isBalanced() check in DefaultRebalancePolicy to the CH factory

Allows waitForRehashToComplete() to work even if the CH factory allocated
less than numOwners owners to each segment.