Save object attribute data to the historian

Some attribute values can be saved as historical data when values change. Data quality and time are also associated with attribute values. When available, Application Server uses the attribute’s value, the timestamp when the value changed, and the calculated quality of the data to create a Value, Time, Quality (VTQ) packet sent to the Historian. If there is no timestamp associated with the attribute value, the current scan time from the AppEngine hosting the object is used instead.