+JH/20 Bug 2389: fix server advertising of usable certificates, under GnuTLS in
+ directory-of-certs mode. Previously they were advertised despite the
+ documentation.
+
+JH/27 Bug 2404: Use the main-section configuration option "dsn_from" for
+ success-DSN messages. Previously the From: header was always the default
+ one for these; the option was ignored.
+