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 the will to configure more SMTP servers after configuring phabricator.com
Reviewed By: jungejason
Reviewers: jungejason, tuomaspelkonen, aran
CC: aran, epriestley, jungejason
Differential Revision: 226
