Refs #3809 - Stabby lambda syntax for oneliners

I started by spotting log.rb which didn't have a lambda wrapping its
default scope, as needed by Rails 4. Since the style guide and most
Rails 4 documents used the stabby lambda, I turned on the cop so that we...

fixes #1213 - Get email reports of audit changes

fixes #9795 - check if mail is enabled before sending a notification

fixes #8049 - Add timezone to user

fixes #7586, #7734, #7172 - user preferences for receiving mail notifications

Adds a framework for user-selectable mail notifications. The work is
still done in ActionMailer classes and launch by rake in cron, however a
wrapper called MailNotification is used to provide RBAC and make the...