Merge branch 'make-reply-to-work-everywhere' into 'master'

Make Reply-To config apply to change e-mail confirmation and other notifications sent through Devise

Notifications sent through Devise were using the default From: address, and due to a broken test line nothing was actually being run.

The only way to customize the Devise Reply-To field is to use a custom mailer. Moved the e-mail configuration out of the initializers to accommodate this.

Closes #1556

See merge request !596