Changes around email support

- Added node-mailer module, wrapped it Mailer class which can be invoked
  by calling app.mailer.send()
- Including support for Polyglot on the server-side
Added support for logger, 'from' address
Now requiring 'fromAddress'
Merge pull request #575 from adaptlearning/ABU-336-nodemailer-support

Abu 336 nodemailer support