Result code for invalidated associations

[Hallvard B Furuseth <h.b.furuseth@usit.uio.no>]

The subthread of 'authmeth-12 review notes' about invalidated
associations, with this message of 28 Sep 2004 23:56:43 as its 'tail':
  http://www.openldap.org/lists/ietf-ldapbis/200409/msg00061.html
suggests some changes that involve [protocol].

1. Due to invalidated associations, a better name for strongAuthRequired
   would be strongerAuthRequired - or even authRequired or bindRequired
   (I added the latter since anonymous bind is not exactly authentication.)

2. If we instead use invalidCredentials to indicate invalidated
   associations as I suggested, that must be reflected in [Protocol].

-- 
Hallvard