Allow yml messages to be configured by not using engine locales, which, due to a Rails bug, always have higher priority than application locales

lib/devise.rb

@@ -66,6 +66,7 @@ end
 Rails.configuration.after_initialize do
   ActiveRecord::Base.extend Devise::ActiveRecord
   ActiveRecord::ConnectionAdapters::TableDefinition.send :include, Devise::Migrations
+  I18n.load_path.unshift File.expand_path(File.join(File.dirname(__FILE__), 'devise', 'locales', 'en.yml'))
 end
 
 require 'devise/warden'

lib/devise/locales/en.yml

@@ -0,0 +1,18 @@
+en:
+  devise:
+    sessions:
+      signed_in: 'Signed in successfully.'
+      signed_out: 'Signed out successfully.'
+      unauthenticated: 'You need to sign in or sign up before continuing.'
+      unconfirmed: 'You have to confirm your account before continuing.'
+      invalid: 'Invalid email or password.'
+    passwords:
+      send_instructions: 'You will receive an email with instructions about how to reset your password in a few minutes.'
+      updated: 'Your password was changed successfully. You are now signed in.'
+    confirmations:
+      send_instructions: 'You will receive an email with instructions about how to confirm your account in a few minutes.'
+      confirmed: 'Your account was successfully confirmed. You are now signed in.'
+    notifier:
+      confirmation_instructions: 'Confirmation instructions'
+      reset_password_instructions: 'Reset password instructions'
+