make nuspec's consistent
Missed period.
1. Added copy constructor for TokenValidationParameters
2. Fixed broken tests
3. Modified IdentityComparer to reduce code redundancy
4. Saml1 and Saml2 ReadToken marked override rather than virtual
5. AudienceValidator throws SecurityTokenInvalidAudienceException
6. Added shell for IExpirableNonceCache
Merge pull request #8 from brentschmaltz/dev

1. Added copy constructor for TokenValidationParameters
Metadata retrieval infrastructure.
Update unit tests for metadata infrastructure.
Rename Metadata to Configuration. Cleanup retrieval flow.
Trim configuration public footprint.