Release 1.4.0

This release includes updates to make it easier to marshal the model objects with libraries like Jackson
when exposed over REST API.

Example:

{
    "pp_key": 24,
    "date": "2015-11-16T10:00:00.000+00:00",
    "title": "Hosted Application Subscription 2015-2016",
    "editable": false,
    "profit": 0.00,
    "type": 0,
    "status": "Approved",
    "authorized": "2015-11-16T05:00:00.000+00:00",
    "key": {
        "keys": [
            {
                "key": "pr_key",
                "value": 45
            }
        ]
    },
    "id": 45,
    "new": false
}

Model and API breaking changes have been introduced here.
A bit of refactoring will be needed if library used extensively