+PH/21 On the advice of Timo Sirainen, added a check to the dovecot
+ authenticator to fail if there's a tab character in the incoming data
+ (there should never be unless someone is messing about, as it's supposed
+ to be base64-encoded). Also added, on Timo's advice, the "secured" option
+ if the connection is using TLS or if the remote IP is the same as the
+ local IP, and the "valid-client-cert option" if a client certificate has
+ been verified.
+
+PH/22 As suggested by Dennis Davis, added a server_condition option to *all*
+ authenticators. This can be used for authorization after authentication
+ succeeds. (In the case of plaintext, it servers for both authentication
+ and authorization.)
+
+PH/23 Testing for tls_required and lost_connection in a retry rule didn't work
+ if any retry times were supplied.
+