Wrote a new buffering email logger

This new log handler uses the Preferences system for its basic settings — SMTP user and password, server and port, as well as the email sender, recipients and default subject. All those can be overridden by the calling app.

Note that BackupMonkey has NOT yet been rewritten to use the new logger. That's next on the to-do list.
Tweaked a few changes to EmailLogHandler

Has a global debug flag in the prefs plist now. Also intelligently forces recipients to be an array allatimes. Also also found a wee little print statement hiding down in the guts which I responsibly excised.
The Monkey now uses the new EmailLogHandler

It also gets a sensible-defaults preferences file.
Merge branch 'feature/Email_breakout' into develop