Fix assmbly for mvn clean install -Papache-release and update version to SNAPSHOT for SNAPSHOT release.

Trace segment compute by http json stream test success.

Provide new stage of module initialization. Named `notifyAfterCompleted`. And rename `init` stage to `start`. Now the initialization sequence is prepare -> start -> notifyAfterCompleted

1. Success: send to analytic worker
2. Failure: write into file.

because of remove the collection item action inside of collection for each action.

The commit code in ClusterZKDataMonitor's 'process' method,fixed the collector online/offline bug. By 'client.getChildren\(event.getPath\(\), true\);', collector can't get the deleted node. In fact,ClusterZKDataMonitor listening zookeeper 'onNodeChanged' event by use 'if \(listeners.containsKey\(event.getPath\(\)\)\)'.

When collector server restart at short intervals that zookeeper will not find remove this server path.
But in another situation, there was a same address server has been running, the restart server could not remove this path and recreate it.
So when this situation happened, throw exception to stop this restart server.