Initial scaffolding for user messaging
Merge branch 'master' into user_messages
More work on user messaging
More work on user messaging.
 - Added flag to account to allow disabling messaging
 - Allow updating account prefs from edit profile page
 - Rationalised logic for determining if a user can be messaged
 - Added tests
A few more tweaks and fixes to messaging
Merge branch 'master' into user_messages

Conflicts:
	modules/portal/app/controllers/portal/Social.scala
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