Summary:
Ref T4107. Two issues:
- With strict MySQL settings, we try to insert `null` into the non-nullable `messageCount` field. Add an `initializeNew...` method.
- If we don't create a new conpherence (for example, because the message body is empty), we fatal on `getPHID()` right now.
Also, make this stuff a little easier to test.
Test Plan: Used `mail_handler.php` to receive empty conpherence mail, and new-thread conpherence mail.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T4107
Differential Revision: https://secure.phabricator.com/D7760
7f45824984