Compatibility with Microsoft ADFS 2.0

Added a short Read Me text file with steps to follow in order to use
PAC4J against ADFS.
Modified SAML2 response validation. NameID is not needed if at least one
Subject Confirmation is present (even without a NameID). BaseID is also
accepted. If NameID is empty, a dummy NameID is used for SAML2
credentials.
Hi Ben, Thank you for the link, I will study it. The ADFS I will connect to belongs to another company and I have no control over it, so I cannot assure the Name ID will come. And I know it does not come by default, I used a freshly installed test ADFS with a newly configured trust.