The mid-tier of console messenger supports save a new message, get all the message belongs to a user and delete the expired messages in persistence layer.

It is mainly used by the console messenger widget, also exploiter can use the MessengerHelper to save asych messages.

By default it will create a schduled job using Spring scheduling to figure out and delete expired message every 72 hours.
Also exploiters can call the ConsoleMessenger to delete expired msg manully.