Filter attribute release depending on CAS service groups

[Cantor, Scott]

> InEntityGroup does not seem to work and RequesterRegex does seem to
> have the problem, that it potentially also applies to all SAML SPs with such
> an entityID.

I was under the impression that the CAS code was mocking up metadata objects that would include the bits sufficient to make InEntityGroup work. If not, it's probably possible to enhance that.

-- Scott