Pymta

- support Python 3.9

- support AUTH LOGIN

- pymta now also supports Python 3 (contributed by Alex Grönholm)
- require pycerberus >= 0.5 to simplify some validation code
- dropped support for Python 2.3-2.6 (still supporting Python 2.7)

- Fix bug - detect of command/message also when the terminator is sent in
multiple packages (fixes manual message submission with telnet)

- Fix egg file generation: Include all necessary packages in eggs

- Dropped dependency to repoze.workflow because the module added a lot of
dependencies recently (six others in total). The new, custom state machine
also supports flags and conditions which suits SMTP very much.
- Added dependency to pycerberus (>= 0.3.1) to validate all sent parameters
thoroughly with sensible error messages.
- All inputs from peers is now validated
- relaxed restrictions for the HELO/EHLO parameter (as real world clients don't
send real host names)
- Fixed bug - ESMTP session switched back to plain SMTP after the first mail
was sent
- Fixed bug - Hang after sending data to a broken connection