Merge pull request #3792 from gschlager/i18n-patch3

FIX: I18n.exists? should use locale fallbacks

lib/freedom_patches/i18n_fallbacks.rb

@@ -0,0 +1,17 @@
+module I18n
+  module Backend
+    module Fallbacks
+      def exists?(locale, key)
+        I18n.fallbacks[locale].each do |fallback|
+          begin
+            return true if super(fallback, key)
+          rescue I18n::InvalidLocale
+            # we do nothing when the locale is invalid, as this is a fallback anyways.
+          end
+        end
+
+        false
+      end
+    end
+  end
+end