Continued segregating the email protocol tests, into their own protocol
based ranges, in preparation of adding more e-mail related tests to the
test suite.
They were all wrong previously since none used the <brackets> they
should for MAIL FROM. Now libcurl adds them itself if the app doesn't so
they end up wrong less easy.
- SMTP falls back to RFC821 HELO when EHLO fails (and SSL is not required).
- Use of true local host name (i.e.: via gethostname()) when available, as default argument to SMTP HELO/EHLO.
- Test case 804 for HELO fallback.
