R1:25dee6ecd2a0

Support email replies in Phabricator

Summary:
Provides support for per-user x per-object unique reply-to email addresses, plus
SMTP integration.

This does not actually make Phabricator use these in outbound email.

Test Plan:
Used test console to validate in-Phabricator routing and handling.

Piped emails into the "mail_handler.php" script to validate mail parsing.

Configured sendmail and sent mail to Phabricator.

Technically I haven't conducted all parts of this test on the same machine since
I lost…