properly in angle brackets. Recipients provided with CURLOPT_MAIL_RCPT now
get angle bracket wrapping automatically by libcurl unless the recipient
starts with an angle bracket as then the app is assumed to deal with that
properly on its own.
sequences in uploaded data. The test server doesn't "decode" escaped dot-lines
but instead test cases must be written to take them into account. Added test
case 803 to verify dot-escaping.