Change "idpdisco.url.saml2" to "idpdisco.url.saml20", to be consistent with...

Change "idpdisco.url.saml2" to "idpdisco.url.saml20", to be consistent with the rest of simpleSAMLphp. Also include a forgotten change from the last patch.


git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@616 44740490-163a-0410-bde0-09ae8108e29a