Web service changes only.

• Added a health check API to the http(s) interface:

[GET] http://{serviceURL}/API/face/Health will return (200) OK if everything is properly initialised or a (500) Internal Server Error if not. Also initialises the website and loads the Face Match models if the service is being used for the first time.

• The service also has a version API:

[GET] http://{serviceURL}/API/face/Version will return (200) OK and a utf-8 string containing the version number.