@Override
    public void initialize(XMPPServer server) {
        super.initialize(server);
        infoHandler = server.getIQDiscoInfoHandler();
        itemsHandler = server.getIQDiscoItemsHandler();
        messageStore = server.getOfflineMessageStore();
        userManager = server.getUserManager();
        routingTable = server.getRoutingTable();
    }
Implements JEP-0013: Flexible Offline Message Retrieval. Allows users to request number of
messages, request message headers, retrieve specific messages, remove specific messages,
retrieve all messages and remove all messages.

@author Gaston Dombiak
xmppserver/src/main/java/org/jivesoftware/openfire/handler/IQOfflineMessagesHandler.java