Want to tweak some, but start to displaying base generic message via javascript.
Automatically clear the errors when re-displayed. Not sure if this is ideal functionality.
Merge branch 'master' into feature/authentication_generic_error

Conflicts:
	app/views/layouts/_messages.html.haml
	app/views/layouts/application.html.haml
	users/app/assets/javascripts/users.js.coffee
Merge branch 'master' into feature/authentication_generic_error
Clear authentication errors before displaying new ones.
Slight cleanup due to some emacs annoyances.
Slight tweak in case we get back the default response to warden's fail!, which is not an enumerable.