dramatically simplify the before_type_cast hack and remove read method override

simplified write method with no dirty attributes hackery

lib/validates_timeliness.rb

@@ -45,6 +45,7 @@ module ValidatesTimeliness
     def setup_for_rails
       self.default_timezone = ::ActiveRecord::Base.default_timezone
       self.use_time_zones = ::ActiveRecord::Base.time_zone_aware_attributes rescue false
+      self.enable_active_record_datetime_parser!
       load_error_messages
     end
   end