This represents a credential store that can test a bind to the persistence mechanism using provided credentials.
Used in combination with a BindUsernamePasswordAuthScheme allows JOSSO to delegate authentication process to the
underlaying persistence mechanism, for example a DB or LDAP server like MS AD.
author: Sebastian Gonzalez Oyuela version: $Id: BindableCredentialStore.java 508 2008-02-18 13:32:29Z sgonzalez $