Stops the embedded web server.
The 'callback' parameter specifies a function which will be called when the operation completes (or an error is encountered). If the 'callback' parameter is not specified, then the method will block and will not return until the operation completes (or an error is encountered).
The callback for this method is defined as:
'err' is the error that occurred. If there was no error, then 'err' is 'null'.
'err' has 2 properties which hold detailed information:
Stops the embedded web server. Under normal circumstances the web server will be stopped automatically during the authorization process when GetAuthorization is called. If ReUseWebServer is set to true the server will not be automatically stopped, and this method must be called to stop the embedded web server.