toJSON() fails on toData() when have a ReferenceProperty (Datastore api)

[leite]

here is the patch ...

\lib\google\appengine\ext\db\model.js
line: 357
/*
*/
Model.prototype.toData = function () {
var data = { key: this.key().toString() }
var properties = this.constructor.properties();
//
for (var i in properties) {
var prop = properties[i];

    if( typeof(this[prop.name])=='object' ){
        data[prop.name] = this[prop.name].toData();
    }else{
        data[prop.name] = this[prop.name];
    }

}
return data;

}
/**/