Rather not promote use of the old schema.

holds a single attribute type 'componentTest'.  Fix
up test031 to avoid modification of standard schema.
(Not sure why this attribute is needed, tests likely
should operate on userCertificate and other existing
attributes which complex syntaxes.)

Misc Clean.

returned for Bind operations, instead invalidCreditials
should be returned.

This had the effect of setting the result code to LDAP_SUCCESS for modlist == NULL
even on a replica when an update-ref might be set. This was causing a plugin (that
implements the commit phase in a post-op plugin) to write to "read-only" replica.

macro).  Add comment indicating configure test needed.