title: jQuery.ajax doesn't send Authorization header with OPTIONS request
body: <p>It appears that jQuery doesn't send along the <code>Authorization</code> header when sending an <code>OPTIONS</code> request before a <code>POST</code> request (or possibly other types). The server I'm trying to reach is returning a 401 status for the <code>OPTIONS</code> request - how can I force jQuery to include the <code>Authorization</code> header, even in this initial request?</p>
  
  <pre><code>$.ajax({
      type: "POST",
      url: url,
      data: postData,
      beforeSend: function ajaxBeforeSend(jqXHR) {
          jqXHR.withCredentials = true;
          jqXHR.setRequestHeader("Authorization", "Basic " + btoa(encodeURIComponent(escape($username.val())) + ":" + encodeURIComponent(escape($password.val()))));
      },
      success: runReportUrlCallback,
      error: runReportErrorCallback
  });
  </code></pre>
  
  <p>I also tried adding <code>username</code> and <code>password</code> to the ajax options, to no avail.</p>