Message storage
Messages are stored in the messages workspace. Each user has its own
subnode under the workspace root.
/superuser
  /0
  /1
/peter
  /2
    cleared true
    id 2
    message Revised the abstract. Please review.
    messageView workflow:workflow
    messageType WORKITEM
    sender eric
    subject Publication request for page /travel/about/careers
    timestamp 1377865432883
    workitemId 1377264630284
/eric
  /0The numbered nodes (0, 1, 2 etc.) under the users are the messages.
Their node type is
mgnl:systemMessage.
Message properties:
- 
cleared. Whether the message has been read or not.true/false
- 
id. Identifies the message. The message ID is unique inside the user node.
- 
message. Text of the message.
- 
messageView. Message view definition name prefixed by the name of the module where the view is configured.
- 
messageType. INFO, WORKITEM, WARNING or ERROR. Defined in info.magnolia.ui.api.message.MessageType.
- 
sender. Name of the sending user.
- 
subject. Subject line.
- 
timestamp. Time when the message was sent.
- 
workItemId. For workflow messages, an ID of the workitem.