title: "properties should not be accessed directly" issue during WooCommerce 3.0 checkout
body: <p>My log shows a lot of the following messages:</p>
  <blockquote>
  <p>order_total was called incorrectly. Order properties should not be accessed directly. This message was added in version 3.0.</p>
  </blockquote>
  <p>and it repeats that message for every property on Order.</p>
  <p>What is the cause of these messages and what should I do to rectify them?</p>