GUAC-549: Add status code object and enum.
GUAC-549: Throw status instead of error for connect() in tunnel and client. Pass status instead of message/code parameters for onerror event handlers.
GUAC-549: Use Guacamole.Status for ack messages.
GUAC-549: Use new onerror/onack handlers. Translate Guacamole.Status codes to human-readable messages.