[Models] can't query RootDSE attributes

["Jim Sermersheim" <jimse@novell.com>]

Many of the attributes on the rootDSE are designed such that they cannot
be used in search filters or the compare operation.

altServer, namingContexts, supportedControl, supportedExtension,
supportedLDAPVersion, and supportedSASLMechanisms are all defined
without an EQUALITY matching rule, so a DSA which adheres to [Models]
will not allow these to be compared.

Is there sufficient usefulness in allowing a client to perform a
compare operation against some of these as its method of discovery to
warrant an update to them to include matching rules?

It has also been noted that a similar attribute (supportedFeatures)
does define an EQUALITY rule, thus allowing to be interrogated with
search or compare.

Jim