Add supports(Credentials) method to the AuthenticationMetaDataPopulator interface
updated authn manager to call supports on metadata populators.
Merge branch 'master' into CAS-1058-authnmd-supports
removed double calling of the supports method in individual populators
Fixed test failure
Fixed test failure
Merge pull request #748 from Unicon/CAS-1058-authnmd-supports

Adds supports() to the AuthenticationMetaDataPopulator