title: Get order on observer event
body: <p>im trying to get the order data from the observer, but is returning me null, is happening me only on the "sales_order_credit_memo_save_after", dont understang why is happening in this specific one. The event is for sure loading the right method, but in the order data gets null.</p>
  
  <p>my code here.
  config.xml:</p>
  
  <pre><code>&lt;events&gt;
              &lt;sales_order_save_after&gt;
                  &lt;observers&gt;
                      &lt;ordertest&gt;
                          &lt;type&gt;model&lt;/type&gt;
                          &lt;class&gt;ordertest/observer&lt;/class&gt;
                          &lt;method&gt;createInvoice&lt;/method&gt;
                      &lt;/ordertest&gt;
                  &lt;/observers&gt;
              &lt;/sales_order_save_after&gt;
  
              &lt;sales_order_creditmemo_save_after&gt;
                  &lt;observers&gt;
                      &lt;ordertest&gt;
                          &lt;type&gt;model&lt;/type&gt;
                          &lt;class&gt;ordertest/observer&lt;/class&gt;
                          &lt;method&gt;createCredit&lt;/method&gt;
                      &lt;/ordertest&gt;
                  &lt;/observers&gt;
              &lt;/sales_order_creditmemo_save_after&gt;
          &lt;/events&gt;
  </code></pre>
  
  <p>Observer:</p>
  
  <pre><code>public function createCredit($observer) {
          $order = $observer-&gt;getEvent()-&gt;getOrder();
  var_dump($order);
  die;
  </code></pre>