Hide the grandmaster port state.

There really is no such state, but there probably should have been one.
In any case, we do have one just to make the code simpler, but this should
not appear in the management responses. This patch fixes the issue by
covering over our tracks before sending a response.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Add a coding style document.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>