Merged in issue-491 (pull request #333)
https://bitbucket.org/openid/fapi/issues/491/link-attacker-model-to-fapi-2-advanced
https://bitbucket.org/openid/fapi/issues/401/use-of-the-phrase-non-repudiation
https://bitbucket.org/openid/fapi/issues/491/link-attacker-model-to-fapi-2-advanced
https://bitbucket.org/openid/fapi/issues/401/use-of-the-phrase-non-repudiation