by Tang Tong.
** libgnutls: addition of support for TLS 1.2 signature algorithms
-extension and certificate verify field.
+extension and certificate verify field. This requires changes for
+TLS 1.2 servers and clients that use callbacks for certificate retrieval.
+They are now required to check with gnutls_session_sign_algorithm_get_requested()
+whether the certificate they send complies with the peer's preferences in
+signature algorithms.
** libgnutls: In server side when resuming a session do not overwrite the
initial session data with the resumed session data.