Appointment status logs using appointment_status_history data model

Currently, the Appointment Scheduling module provides a "appointment_status_history" table for tracking the history of appointment statuses.  There are a few limitations of this currently, however:

• When interacting with the Appointment Scheduling module RESTfully the status is not automatically updated (so when using the UI provided by the Appointment Scheduling UI module, the status is not tracked)
• The table does not include the current status, only historical statuses... this was by design, but is non-intuitive, and also makes it hard to work with RESTfully

We would like to:

• Update the Appointment Resource so that when a appointment is saved RESTfully it's status is updated if needed
• Change the history so that it stores the current status as well as historical statuses