Replace handover in Akka 2.2.x with persistence in Akka 2.3.x+

[ngocdaothanh]

http://doc.akka.io/docs/akka/2.3.0/project/migration-guide-2.2.x-2.3.x.html
http://doc.akka.io/docs/akka/2.3.0/scala/persistence.html

Removed hand over data in cluster singleton:
The support for passing data from previous singleton instance to new instance in a graceful leaving scenario has been removed. Valuable state should be persisted in durable storage instead, e.g. using akka-persistence.

[alessandro-molari]

Is this issue still really open?
Ty

[ngocdaothanh]

Hi,
This issue is still open.
At the mean time, if you want, please implement the state saving and loading by yourself.