Add limit for amount of log events read

There is no limit to the amount of logs JAU will read. In the case of a missing connection to CS, the EventRepo will continuously increase as the repo will never be cleared. All log events will be included in each request to CS, which after some time can result in a lot of outgoing traffic from the agent.

A possible fix would be to limit the amount of events that can be stored in the EventRepo. Must in that case avoid the issue where the event extractor will never catch up to new log events if there has been no contact with CS for a while.