Implements TaskServer on hazelcast version 2.
Merge branch 'feature/hazelcast-backend'
HazelcastTaskServer without queues
Remove unnecessary my HazelcastTaskServer.
HazelcastTaskServer with process lock
Hazelcast checkpoint service +some code clean up
nothing special
Merge remote-tracking branch 'remotes/origin/develop' into snapshots-feature
ProcessBackend interface changed for snapshots wishes