Summary: We can't show this stuff on the web UI because it has password reset links and private reply-to addresses, but we can provide easier CLI tools than "root around in the database". Land a rough version of `bin/mail show-inbound` and `bin/mail show-outbound`.
Test Plan: Used both commands to examine mail from the CLI.
Reviewers: btrahan
Reviewed By: btrahan
CC: tido, euresti, aran
Differential Revision: https://secure.phabricator.com/D5963
