Motivation:
lock management across multiple nfs servers.

Modification:
add Hazelcaset-based subclass of AbstractLockManager. Classes which are
used in lock implementations are updated to implement java.io.Serializible.

NOTICE, that we do not include any (except of hazelcast's own default
config) configuration. Thus end-application can itself decide how
Hazelcast is instantiated and configured.

Result:
locks are honored across set of nfs servers, if configured.

Acked-by: Paul Millar
Target: master