Merge pull request #8 from brentschmaltz/dev

1. Added copy constructor for TokenValidationParameters
1. Additional mormalization of validation between, jwt and saml
2. out parameter on ValidateToken
3. throw not supported for handler methods: ValidateTokne(SecurityToken)
4. Moved RoleClaim and NameClaim delegates to TokenValidationParameters
5. Removed warnings
6. Clone on TokenValidationParameters and OpenIdConnectMessage
7. Audience Validation now takes Enumeration of audiences
8. Created OpenIdConnectProtocolValidator
9. New exceptions and error strings for Nonce and CHash failures
10. Settable defaults on OpenIdConnectMessage for creation of methods
11. Fixed tests for new OM
Merge branch 'dev' of https://github.com/MSOpenTech/azure-activedirectory-identitymodel-extensions-for-dotnet into dev
Metadata retrieval infrastructure.
Update unit tests for metadata infrastructure.
Rename Metadata to Configuration. Cleanup retrieval flow.
Trim configuration public footprint.
Clean up WsFed metadata processing.
Clean up cancellation flow in the config manager.
Merge pull request #11 from Tratcher/dev

Configuration retrieval infrastructure
Model change, change inheritance from S.IM.Saml to S.IM.SecurityTokenHandler.
Remove Saml/Saml2/JwtSecurityTokenRequirements, properties to TokenValidationParameters