R1:193dbf16b4d7

Very basic daemon infrastructure, plus MetaMTA daemon.

Summary: Amazon SES seems to be working well, except that it takes more than a
second to send mail in-process. Kick it out of process. (Between this and the
ImplementationAdapter layer, MetaMTA almost makes sense. :/)

Test Plan: Ran the daemon and got a flood of unsent test email.

Reviewers:

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