Replaces sendmail with direct

Closes #1538
* rips out sendmail
* adds direct
* updates nodemailer to 0.7.1
* changes unit tests for mail
* changes integration tests for mail
* adds api tests for mail
Keep the messages consistent -- if the error was that you "failed to deliver", then the completion is you "successfully delivered", no?  "Message was accepted by your mail server" is all like, whaaa