Base: Allow an IdP to indicate that it provides only an AA.

References #140.

With this set to true metadata rendering should only output the
AttributeAuthorityDescriptor and not the IDPSSODescriptor within
the EntityDescriptor.
Metadata: Don't Render IDPSSODescriptor in AA only mode.

References #140.

Ensures that an IDPSSODescriptor which indicates it is actually only
acting as a AttributeAuthorityDescriptor does not have an
IDPSSODescriptor added to Metadata.
Base: Allow administrators to set IdP to AttributeAuthority only.

References #140.
Base: Have BuildConfig correctly reference versioned FederatedGrails.

Plugin location was pointing to local development on disk in error.
This change correctly points it to FederatedGrails 0.6.0.
Merge pull request #140 from ausaccessfed/feature/#140-allow-idp-marked-aa-only

Allow IdP to be marked as AA only